Public Discourse Against Masks in the COVID-19 Era: Infodemiology Study of Twitter Data

BackgroundDespite scientific evidence supporting the importance of wearing masks to curtail the spread of COVID-19, wearing masks has stirred up a significant debate particularly on social media.ObjectiveThis study aimed to investigate the topics associated with the public discourse against wearing masks in the United States. We also studied the relationship between the anti-mask discourse on social media and the number of new COVID-19 cases.MethodsWe collected a total of 51,170 English tweets between January 1, 2020, and October 27, 2020, by searching for hashtags against wearing masks. We used machine learning techniques to analyze the data collected. We investigated the relationship between the volume of tweets against mask-wearing and the daily volume of new COVID-19 cases using a Pearson correlation analysis between the two-time series.ResultsThe results and analysis showed that social media could help identify important insights related to wearing masks. The results of topic mining identified 10 categories or themes of user concerns dominated by (1) constitutional rights and freedom of choice; (2) conspiracy theory, population control, and big pharma; and (3) fake news, fake numbers, and fake pandemic. Altogether, these three categories represent almost 65% of the volume of tweets against wearing masks. The relationship between the volume of tweets against wearing masks and newly reported COVID-19 cases depicted a strong correlation wherein the rise in the volume of negative tweets led the rise in the number of new cases by 9 days.ConclusionsThese findings demonstrated the potential of mining social media for understanding the public discourse about public health issues such as wearing masks during the COVID-19 pandemic. The results emphasized the relationship between the discourse on social media and the potential impact on real events such as changing the course of the pandemic. Policy makers are advised to proactively address public perception and work on shaping this perception through raising awareness, debunking negative sentiments, and prioritizing early policy intervention toward the most prevalent topics.     

Modified full-face snorkeling mask for thoracic surgery and otolaryngology surgical use: comfort and usability assessment during the COVID-19 pandemic

Background:A worldwide personal protection equipment (PPE) shortage has emerged during COVID-19 pandemic, contributing to the high incidence of SARS-CoV-2 infection among health care providers. To address this lack of PEE, new solutions have been researched. Among those, full-face snorkeling masks demonstrated to be an interesting option. Among surgical specialties otolaryngologists and thoracic surgeons are at high risk of infection, due to the close contact with airway secretions.Objectives:We tested the comfort and usability of a modified full-face snorkeling mask (Ocean Reef Mask Aria QR+) as a protective device for otolaryngologic and thoracic surgeries.Methods:The mask was customized with a 3D-printed adaptor supporting many industrial filter types, including FFP3 and heat and moisture exchangers (HME). We evaluated surgical performances of the mask, both subjectively, with a questionnaire filled in by the surgeons, as well as objectively, monitoring transcutaneous PCO₂ and PO₂ values of surgeons during surgical procedures.Results:The modified full-face snorkeling mask was tested during 9 otolaryngologic and 15 thoracic surgery procedures. The device demonstrated very good overall vision quality with some limitations regarding lateral vision and almost no difficulties in usability. Water condensation into the mask was absent in almost every case. Both PO₂ and PCO₂ parameters remained within normal ranges during every procedure.Discussion:The modified full-face snorkeling mask can be an innovative PPE. In the current COVID-19 pandemic scenario, the worldwide shortage of protective masks and goggles may exploit this ready-to-use and low-cost solution, especially for high-risk surgical procedures.     

Brief Cost Analysis of Surgical Personal Protective Equipment During the COVID-19 Pandemic

ObjectivesThis study aimed to compare the costs incurred and saved from universal use of N95 respirators with surgical masks for operating room providers in the United States during the COVID-19 pandemic.MethodsWe built a decision analytic model to compare direct medical costs of healthcare workers (HCWs) infected with COVID-19 during operating room procedures from expected transmission when using an N95 respirator relative to a surgical mask. We also examined quarantine costs.ResultsResults varied depending upon prevalence and false-negative rates of tests, but if N95 respirators reduce transmission by 2.8%, prevalence is at 1%, and testing yields 20% false negatives, providers should be willing to pay an additional $0.64 per HCW for the additional protection. Under this scenario, approximately 11 COVID-19 cases would be averted among HCWs per day.ConclusionsPotential savings depend on disease prevalence, rate of asymptomatic patients with COVID-19, accuracy of testing, the marginal cost of respirators, and the quarantine period. We provide a range of calculations to show under which conditions N95 respirators are cost saving.     

Transmission dynamics of COVID-19 in Algeria: The impact of physical distancing and face masks

We propose an SIR epidemic model taking into account prevention measures against coronavirus disease 2019 (COVID-19) such as wearing masks and respecting safety distances. We look for the conditions to avoid a second epidemic peak in the phase of release from confinement. We derive equations for the critical levels of mask efficiency, mask adoption (fraction of population wearing masks) and fraction of population engaging in physical distancing that lower the basic reproduction number ℜ₀ to unity. Conclusions: For ℜ₀ = 2.5, if at least 40% of people wear masks with efficiency 50%, and at least 20% of the population without masks (or anti-maskers) respect physical distancing measures, the effective reproduction number can be reduced to less than 1 and COVID-19 infections would plummet. The model predicts also that if at least half of the people respecting physical distancing, COVID-19 outbreaks with ℜ₀ of about 3, would be theoretically extinguished without wearing masks. The results of this study provide an alternative explanation for the spread of the disease, and suggest some valuable policy recommendations about the control strategies applied to mitigate disease transmission.     

Surgical masks vs filtering facepiece respirators for the protection against coronavirus infection: current state of the art

Background:During the Covid-19 outbreak, a recurrent subject in scientific literature has been brought back into discussion: whether surgical masks provide a sufficient protection against airborne SARS-CoV-2 infections.Objectives:The objective of this review is to summarize the available studies which have compared the respective effectiveness of surgical masks and filtering facepiece respirators for the prevention of infections caused by viruses that are transmitted by the respiratory tract.Methods:The relevant scientific literature was identified by querying the PubMed database with a combination of search strings. The narrower search string “(surgical mask *) AND (respirator OR respirators)” included all the relevant articles retrieved using broader search strategies. Of all the relevant articles found, seven systematic reviews were selected and examined.Results:The currently available scientific evidence seems to suggest that surgical masks and N95 respirators/FFP2 confer an equivalent degree of protection against airborne viral infections.Discussion:Since surgical masks are less expensive than N95 respirators but seem to be as effective in protecting against airborne infection and they are also more comfortable for the user, requiring less respiratory work, they should be the standard protective device for health care workers and especially for workers who carry out non-medical jobs. Filtering facepiece respirators, whose extended use is less comfortable for the wearer, may be preferred for procedures which require greater protection for a shorter time.Key words: Surgical masks, filtering facepiece respirators, aerosols, droplets, SARS-CoV-2, Covid-19     

Adherence to Personal Protective Equipment Use in Home-Care Service Agencies During COVID-19 in Japan: A Cross-Sectional Survey

ObjectivesTo assess adherence to personal protective equipment (PPE) use among home care workers during usual care at the agency level during the COVID-19 pandemic in Japan and determine whether agency-level action toward infection prevention and control (IPC) is associated with adherence to PPE use.DesignA nationwide cross-sectional study.Setting and ParticipantsHome care service agencies in Japan were randomly selected from all agencies nationwide.MethodsAn online survey was conducted between January and February 2021. The administrators at home care service agencies responded to the following items: adherence to PPE (disposable masks, gloves, and aprons) use during diaper change among their home care workers, agency-level actions toward IPC, including monitoring of infection outbreak among users, existing manual for IPC, training opportunities on IPC for care workers, and other agency and administrator characteristics.ResultsOf the 1942 agencies, 197 were included in the analysis (response rate: 10.1%). Although 145 (73.6%) of the agencies always used both masks and gloves during diaper change, 32 (16.2%) agencies fully adhered to wearing masks, gloves, and aprons. Agencies monitoring infectious disease outbreaks among service users were more likely to adhere to PPE use (adjusted odds ratio: 5.97, 95% confidence interval: 1.30–27.31).Conclusions and ImplicationsLow adherence to PPE use, especially apron use, during diaper change among home care service agencies during the COVID-19 pandemic in Japan was revealed, despite the widespread availability of a manual for IPC and/or training opportunities. To ensure safety and quality home care services for both users and home care workers, agencies should not simply create manuals or training systems as a structure; instead, they should implement effective processes for appropriate PPE use.     

Particle Filtration Efficiency Testing of Sterilization Wrap Masks

ObjectivesNon-traditional materials are used for mask construction to address personal protective equipment shortages during the coronavirus disease 2019 (COVID-19) pandemic. Reusable masks made from surgical sterilization wrap represent such an innovative approach with social media frequently referring to them as “N95 alternatives.” This material was tested for particle filtration efficiency and breathability to clarify what role they might have in infection prevention and control.MethodsA heavyweight, double layer sterilization wrap was tested when new and after 2, 4, 6, and 10 autoclave sterilizing cycles and compared with an approved N95 respirator and a surgical mask via testing procedures using a sodium chloride aerosol for N95 efficiency testing similar to 42 CFR 84.181. Pressure testing to indicate breathability was also conducted.ResultsThe particle filtration efficiency for the sterilization wrap ranged between 58% to 66%, with similar performance when new and after sterilizing cycles. The N95 respirator and surgical mask performed at 95% and 68% respectively. Pressure drops for the sterilization wrap, N95 and surgical mask were 10.4 mmH₂O, 5.9 mmH₂O, and 5.1 mmH₂O, respectively, well below the National Institute for Occupational Safety and Health limits of 35 mmH₂O during initial inhalation and 25 mmH₂O during initial exhalation.ConclusionsThe sterilization wrap’s particle filtration efficiency is much lower than a N95 respirator, but falls within the range of a surgical mask, with acceptable breathability. Performance testing of non-traditional mask materials is crucial to determine potential protection efficacy and for correcting misinterpretation propagated through popular media.     

医务人员佩戴医用防护口罩行为现状及其影响因素

目的 了解医务人员佩戴医用防护口罩的行为现状, 并分析未能规范佩戴医用防护口罩的影响因素, 为改进口罩佩戴相关培训提供依据。 方法 2022年6月—2023年3月, 选取某三级甲等医院的工作人员为研究对象, 采用气溶胶凝结核计数法对市面上常见的5款医用防护口罩进行实时定量适合性测试, 通过测试仪器适合因数的变化、是否需要专业人员辅助调整综合判断医用防护口罩佩戴情况, 应用自制的一般资料调查表对参与者进行问卷调查, 借助三维(3D)激光扫描技术扫描参与者头面部, 将扫描图像导入Geomagic Studio 2013软件测量头面部尺寸。 结果 共调查222名医务人员, 完成991次实时测试, 208次3D扫描。其中221次(22.30%)测试参与者未能规范佩戴医用防护口罩, 5款医用防护口罩的不规范佩戴比率分别为30.56%、25.62%、25.87%、23.15%、7.35%。佩戴口罩不规范率: 不同医用防护口罩形状, 参与者职业、上一次医用防护口罩佩戴技能培训时间及是否有呼吸道传染病防治相关工作经验各组比较, 差异均有统计学意义(均P＜0.05);医用防护口罩品牌、尺寸, 以及参与者性别、科室等各组比较, 差异无统计学意义(均P＞0.05)。折叠状医用防护口罩佩戴规范与不规范者身体质量指数(BMI)比较, 差异均有统计学意义(均P＜0.05)。 结论 医务人员佩戴医用防护口罩不规范受诸多因素影响, 在正式的定量适合性测试之前推荐进行实时测试, 能节省时间, 提高测试效率。未来进行医用防护口罩佩戴培训时, 对不同形状的口罩应进行针对性的培训, 重点关注后勤人员、实习生、BMI高者, 以及从未接受医用防护口罩佩戴培训者及未参加过呼吸道传染病防治相关工作者。     

Risky Party and Nightclub Attendance during the COVID-19 Nightlife Shutdown in New York City

From March 2020 through May 2021, nightlife venues were shut down and large gatherings were deemed illegal in New York City (NYC) due to COVID-19. This study sought to determine the extent of risky party attendance during the COVID-19 shutdown among people who attend electronic dance music parties in NYC. During the first four months that venues were permitted to reopen (June through September 2021), time–space sampling was used to survey adults (n = 278) about their party attendance during the first year of the shutdown (March 2020–March 2021). We examined prevalence and correlates of attendance and mask-wearing at such parties. A total of 43.9% attended private parties with more than 10 people, 27.3% attended nightclubs, and 20.5% attended other parties such as raves. Among those who attended any, 32.3% never wore a mask and 19.3% reported attending parties in which no one wore a mask. Past-year ecstasy use was associated with increased risk for attending private (aPR = 1.51, 95% CI: 1.00–2.28) or other parties (aPR = 2.75, 95% CI: 1.48–5.13), and use of 2C series drugs was associated with increased risk for attending nightclubs (aPR = 2.67, 95% CI: 1.24–5.77) or other parties (aPR = 2.50, 95% CI: 1.06–5.87). Attending >10 parties was associated with increased risk for never wearing a mask (aPR = 2.74, 95% CI: 1.11–6.75) and for no other attendees wearing masks (aPR = 4.22, 95% CI: 1.26–14.07). Illegal dance parties continued in NYC during the COVID-19 shutdown. Prevention and harm reduction efforts to mitigate risk of COVID-19 transmission during such shutdowns are sorely needed.     

Jobs,Housing, and Mask Wearing: Cross-Sectional Study of Risk Factors for COVID-19

BackgroundMany studies have focused on the characteristics of symptomatic patients with COVID-19 and clinical risk factors. This study reports the prevalence of COVID-19 in an asymptomatic population of a hospital service area (HSA) and identifies factors that affect exposure to the virus.ObjectiveThe aim of this study is to measure the prevalence of COVID-19 in an HSA, identify factors that may increase or decrease the risk of infection, and analyze factors that increase the number of daily contacts.MethodsThis study surveyed 1694 patients between April 30 and May 13, 2020, about their work and living situations, income, behavior, sociodemographic characteristics, and prepandemic health characteristics. This data was linked to testing data for 454 of these patients, including polymerase chain reaction test results and two different serologic assays. Positivity rate was used to calculate approximate prevalence, hospitalization rate, and infection fatality rate (IFR). Survey data was used to analyze risk factors, including the number of contacts reported by study participants. The data was also used to identify factors increasing the number of daily contacts, such as mask wearing and living environment.ResultsWe found a positivity rate of 2.2%, a hospitalization rate of 1.2%, and an adjusted IFR of 0.55%. A higher number of daily contacts with adults and older adults increases the probability of becoming infected. Occupation, living in an apartment versus a house, and wearing a face mask outside work increased the number of daily contacts.ConclusionsStudying prevalence in an asymptomatic population revealed estimates of unreported COVID-19 cases. Occupational, living situation, and behavioral data about COVID-19–protective behaviors such as wearing a mask may aid in the identification of nonclinical factors affecting the number of daily contacts, which may increase SARS-CoV-2 exposure.     

Factors Affecting Public Non-compliance With Large-scale Social Restrictions to Control COVID-19 Transmission in Greater Jakarta,Indonesia

Objectives:The Indonesian government issued large-scale social restrictions (called Pembatasan Sosial Berskala Besar, or PSBB) at the beginning of the coronavirus disease 2019 (COVID-19) pandemic to control the spread of COVID-19 in Jakarta, Bogor, Depok, Tangerang, and Bekasi (Greater Jakarta). Public compliance poses a challenge when implementing large-scale social restrictions, and various factors have contributed to public non-compliance with the regulation. This study aimed to determine the degree of non-compliance and identify the factors that contributed to public non-compliance with the PSBB in Greater Jakarta, Indonesia.Methods:This was a quantitative study with a cross-sectional design. A total of 839 residents of Greater Jakarta participated in this study. Data were collected online using a Google Form, and convenience sampling was undertaken. Univariate and multivariate analyses were performed to explore the relationships between public non-compliance with the PSBB regulation and socio-demographic variables, respondents’ opinion of the PSBB, and social capital.Results:A total of 22.6% of subjects reported participating in activities that did not comply with the PSBB. The variables that most affected non-compliance with the PSBB were age, gender, income, opinion of the PSBB, and social capital.Conclusions:Strengthening social capital and providing information about COVID-19 prevention measures, such as washing one’s hands with soap, wearing masks properly, and maintaining social distancing, is essential. Robust public understanding will foster trust and cooperation with regard to COVID-19 prevention efforts and provide a basis for mutual agreement regarding rules/penalties.     

COVID-19 pandemic in the United States

ObjectivesThe paper highlights US health policy and technology responses to the COVID-19 pandemic from January 1, 2020 – August 9, 2020.MethodsA review of primary data sources in the US was conducted. The data were summarized to describe national and state-level trends in the spread of COVID-19 and in policy and technology solutions.ResultsCOVID-19 cases and deaths initially peaked in late March and April, but after a brief reduction in June cases and deaths began rising again during July and continued to climb into early August. The US policy response is best characterized by its federalist, decentralized nature. The national government has led in terms of economic and fiscal response, increasing funding for scientific research into testing, treatment, and vaccines, and in creating more favorable regulations for the use of telemedicine. State governments have been responsible for many of the containment, testing, and treatment responses, often with little federal government support. Policies that favor economic re-opening are often followed by increases in state-level case numbers, which are then followed by stricter containment measures, such as mask wearing or pausing re-opening plans.ConclusionsWhile all US states have begun to “re-open” economic activities, this trend appears to be largely driven by social tensions and economic motivations rather than an ability to effectively test and surveil populations.     

Protecting healthcare staff from severe acute respiratory syndrome: filtration capacity of multiple surgical masks

Guidelines issued by the Centers for Disease Control and Prevention and the World Health Organisation state that healthcare workers should wear N95 masks or higher-level protection during all contact with suspected severe acute respiratory syndrome (SARS). In areas where N95 masks are not available, multiple layers of surgical masks have been tried to prevent transmission of SARS. The in vivo filtration capacity of a single surgical mask is known to be poor. However, the filtration capacity of a combination of masks is unknown. This was a crossover trial of one, two, three and five surgical masks in six volunteers to determine the in vivo filtration efficiency of wearing more than one surgical mask. We used a Portacount to measure the difference in ambient particle counts inside and outside the masks. The best combination of five surgical masks scored a fit factor of 13.7, which is well below the minimum level of 100 required for a half face respirator. Multiple surgical masks filter ambient particles poorly. They should not be used as a substitute for N95 masks unless there is no alternative.     

Surgical face masks in the operating theatre: re-examining the evidence

In most modern hospitals, no one is allowed to enter the operating theatre without wearing a surgical face mask. The practice of wearing masks is believed to minimize the transmission of oro- and nasopharyngeal bacteria from operating theatre staff to patients' wounds, thereby decreasing the likelihood of postoperative surgical site infections. In this era of cost-restraints, shrinking hospital budgets, and evidence-based medicine, many health care professionals have begun to re-examine traditional infection control practices. Over the past decade, studies challenging the accepted dogma of surgical face mask usage have been published. Masks that function as protective barriers are another emerging issue. Due to a greater awareness of HIV and other blood-borne viruses, masks are taking on a greater role in protecting health care workers from potentially infectious blood and body fluids. The purpose of this review is to evaluate the latest evidence for and against routine use of surgical face masks in the operating theatre.     

Occupational hand dermatitis web survey in a university hospital during COVID-19 pandemic: the SHIELD study

Background: Occupational hand dermatitis (OHD) is a skin disease occurring on employees’ hands in certain jobs. Little is known about prevalence, incidence and characteristics of this adverse skin reaction and its associated risk factors during COVID-19 pandemic. To evaluate both prevalence and incidence of OHD and associated risk factors in Italian clinicians. Methods: A cross-sectional study was performed using a self-report questionnaire. Results: Two hundred and thirty clinicians responded to the survey and 82% of responders did not report previous OHD history before the COVID-19 pandemic. Daily use of gloves was reported by 80% of responders. OHD prevalence was 18%, while incidence was 80%. We found a protective effect on symptom occurrence for vinyl/nitrile gloves if the time with gloves was ≥ 6 hours per day. Conclusions: This survey reveals a high OHD incidence in an Italian population of clinicians. Furthermore, wearing vinyl/nitrile gloves for at least 6 hours a day had a protective effect on symptom onset.     

COVID-19 Mask Usage and Social Distancing in Social Media Images: Large-scale Deep Learning Analysis

BackgroundThe adoption of nonpharmaceutical interventions and their surveillance are critical for detecting and stopping possible transmission routes of COVID-19. A study of the effects of these interventions can help shape public health decisions. The efficacy of nonpharmaceutical interventions can be affected by public behaviors in events, such as protests. We examined mask use and mask fit in the United States, from social media images, especially during the Black Lives Matter (BLM) protests, representing the first large-scale public gatherings in the pandemic.ObjectiveThis study assessed the use and fit of face masks and social distancing in the United States and events of large physical gatherings through public social media images from 6 cities and BLM protests.MethodsWe collected and analyzed 2.04 million public social media images from New York City, Dallas, Seattle, New Orleans, Boston, and Minneapolis between February 1, 2020, and May 31, 2020. We evaluated correlations between online mask usage trends and COVID-19 cases. We looked for significant changes in mask use patterns and group posting around important policy decisions. For BLM protests, we analyzed 195,452 posts from New York and Minneapolis from May 25, 2020, to July 15, 2020. We looked at differences in adopting the preventive measures in the BLM protests through the mask fit score.ResultsThe average percentage of group pictures dropped from 8.05% to 4.65% after the lockdown week. New York City, Dallas, Seattle, New Orleans, Boston, and Minneapolis observed increases of 5.0%, 7.4%, 7.4%, 6.5%, 5.6%, and 7.1%, respectively, in mask use between February 2020 and May 2020. Boston and Minneapolis observed significant increases of 3.0% and 7.4%, respectively, in mask use after the mask mandates. Differences of 6.2% and 8.3% were found in group pictures between BLM posts and non-BLM posts for New York City and Minneapolis, respectively. In contrast, the differences in the percentage of masked faces in group pictures between BLM and non-BLM posts were 29.0% and 20.1% for New York City and Minneapolis, respectively. Across protests, 35% of individuals wore a mask with a fit score greater than 80%.ConclusionsThe study found a significant drop in group posting when the stay-at-home laws were applied and a significant increase in mask use for 2 of 3 cities where masks were mandated. Although a positive trend toward mask use and social distancing was observed, a high percentage of posts showed disregard for the guidelines. BLM-related posts captured the lack of seriousness to safety measures, with a high percentage of group pictures and low mask fit scores. Thus, the methodology provides a directional indication of how government policies can be indirectly monitored through social media.     

The added effect of non-pharmaceutical interventions and lifestyle behaviors on vaccine effectiveness against severe COVID-19 in Chile: A matched case-double control study

BackgroundWorld Health Organization approved vaccines have demonstrated relatively high protection against moderate to severe COVID-19. Prospective vaccine effectiveness (VE) designs with first-hand data and population-based controls are nevertheless rare. Neighborhood compared to hospitalized controls, may differ in compliance to non-pharmacuetical interventions (NPI) compliance, which may influence VE results in real-world settings. We aimed to determine VE against COVID-19 intensive-care-unit (ICU) admission using hospital and community-matched controls in a prospective design.MethodsWe conducted a multicenter, observational study of matched cases and controls (1:3) in adults ≧18 years of age from May to July 2021. For each case, a hospital control and two community controls were matched by age, gender, and hospital admission date or neighborhood of residence. Conditional logistic regression models were built, including interaction terms between NPIs, lifestyle behaviors, and vaccination status; the model’s β coefficients represent the added effect these terms had on COVID-19 VE.ResultsCases and controls differed in several factors including education level, obesity prevalence, and behaviors such as compliance with routine vaccinations, use of facemasks, and routine handwashing. VE was 98·2% for full primary vaccination and 85·6% for partial vaccination when compared to community controls, and somewhat lower, albeit not significantly, compared to hospital controls. A significant added effect to vaccination in reducing COVID-19 ICU admission was regular facemask use and VE was higher among individuals non-compliant with the national vaccine program, and/or tonroutine medical visits during the prior year.ConclusionVE against COVID-19 ICU admission in this stringent prospective case-double control study reached 98% two weeks after full primary vaccination, confirming the high effectiveness provided by earlier studies. Face mask use and hand washing were independent protective factors, the former adding additional benefit to VE. VE was significantly higher in subjects with increased risk behaviors.     

Surgical masks do not increase the risk of heat stroke during mild exercise in hot and humid environment

Surgical masks are widely used for the prevention of respiratory infections. However, the risk of heat stroke during intense work or exercise in hot and humid environment is a concern. This study aimed to examine whether wearing a surgical mask increases the risk of heat stroke during mild exercise in such environment. Twelve participants conducted treadmill exercise for 30 min at 6 km/h, with 5% slope, 35°C ambient temperature, and 65% relative humidity, while wearing or not a surgical mask (mask and control trials, respectively). Rectal temperature (T_rec), ear canal temperature (T_ear), and mean skin temperature (mean T_skin) were assessed. Skin temperature and humidity of the perioral area of the face (T_face and RH_face) were also estimated. Thermal sensation and discomfort, sensation of humidity, fatigue, and thirst were rated using the visual analogue scale. T_rec, T_ear, mean T_skin, and T_face increased during the exercise, without any difference between the two trials. RH_face during the exercise was greater in the mask trial. Hot sensation was greater in the mask trial, but no influence on fatigue and thirst was found. These results suggest that wearing a surgical mask does not increase the risk of heat stroke during mild exercise in moist heat.