COVID-19 Guidance on the Use of Cloth 

Face Coverings while Working Indoors in 

Hot and Humid Conditions

During the COVID-19 pandemic, OSHA generally recommends that 

employers encourage workers to wear cloth face coverings at work to 

help reduce the spread of COVID-19. However, workers who wear cloth 

face coverings in hot and humid environments or while performing 

strenuous activities indoors, such as those in bakeries, kitchens, 

laundries, electric utilities, fire services, mills, foundries, manufacturing, 

and warehousing, can find cloth face coverings to be uncomfortable.

Employers should follow the below practices to 

protect against the spread of COVID-19 and the 

risk of heat-related illness:

 Acclimatize new and returning workers to 

environmental and work conditions while 

wearing cloth face coverings. 

 Prioritize the use of cloth face coverings

when workers are in close contact with 

others (less than 6 feet), such as during group 

travel or shift meetings. 

 Allow workers to remove cloth face coverings 

when they can safely maintain at least 6 feet 

of physical distance from others. 

 Evaluate the feasibility of wearing cloth 

face coverings for each worker and 

consider alternatives (e.g., face shields) 

when appropriate.

 Increase the frequency of hydration and rest 

breaks in cooled environments.

 Incorporate at least 6 feet of physical 

distancing into break areas by staggering 

breaks, spacing workers, or limiting the 

number of workers on break at a time, 

where feasible.

Photo: USDA
 Enhance ventilation throughout the worksite, 

including in break areas, where feasible.

 Allow workers to return to personal vehicles 

during breaks to use air conditioning, when 

possible. Multiple workers should generally 

not return to the same car.

 If fans are used, avoid directing the fan so it 

pushes air over multiple people at the same 

time, since fans may increase the distance 

respiratory droplets can travel. 

 Encourage workers to use cloth face 

coverings that optimize fit and comfort and 

are made out of breathable, moisturewicking materials. 

 Encourage workers to change cloth face 

coverings when wet, as wet face coverings 

make it more difficult to breathe and are not 

as effective. Provide clean replacement cloth 

face coverings or disposable face masks, as 

needed, for workers to change into 

throughout the work shift.

 Ensure workers use handwashing facilities or 

hand sanitizers with at least 60% alcohol 

often, as heat or moisture build-up may 

cause workers to put on and take off cloth 

face coverings frequently. 

 Allow workers to wear personal passive 

cooling items (e.g., icepack vests, cooling 

bandanas) and loose-fitting and breathable 

clothes, as long as these items do not present 

a safety hazard.

 Plan for heat emergencies and train workers

on heat stress prevention and treatment.

 Increase the frequency of communication to 

workers and encourage workers to monitor 

themselves and others for signs of heat illness.

Note: Cloth face coverings should not be 

considered a substitute for engineering and 

administrative controls, safe work practices, or 

necessary personal protective equipment (PPE). 

For interim guidance and other resources on 

protecting workers from COVID-19, visit OSHA’s 

COVID-19 webpage. 

For guidance and other resources on protecting 

workers from heat stress, visit OSHA’s 

occupational heat exposure webpage. 

For guidance on heat illness prevention during 

the COVID-19 pandemic, visit the Centers for 

Disease Control and Prevention’s webpages for 

workers and employers.

For the latest information on the symptoms, 

prevention, and treatment of COVID-19, visit the 

Centers for Disease Control and Prevention’s

COVID-19 webpage. 

For the latest information on masks, visit the 

Centers for Disease Control and Prevention’s 

COVID-19 and masks webpage.

For the latest information on COVID-19 in 

the workplace, visit the National Institute 

for Occupational Safety and Health’s 

COVID-19 webpage. 