Operating an extreme weather site during COVID-19

COVID prevention guidance for sites that provide temporary respite from wildfire smoke or extreme weather.

Stay healthy during extreme weather


  • Individuals who are sick with COVID-19 should not use an extreme weather site. If they do not have a place to isolate, the COVID-19 Information Warmline can help. Call them at 628-652-2700.
  • Encourage people to wear masks at the extreme weather site, especially those who are high-risk for severe illness from COVID-19.
  • Follow more advice on staying safe in public shelters.
  • In case someone later tests positive for COVID-19: 
    • Keep track of who worked each shift and their contact information.
    • Ask visitors to provide contact information, so you can tell people about an exposure.

Extreme weather

See extreme weather tips for all San Franciscans.

Preparing an extreme weather site

Cleaner air sites are public spaces where people can seek relief from wildfire smoke.

  • Cleaner air sites should have central air conditioning with medium- or high-efficiency filters. 

Cooling sites should have Heating, Ventilation, and Air Conditioning (HVAC) and tall ceilings.

  • Further guidance for cooling centers is available from CDPH and CDC.
  • Adjustments to your HVAC system must follow all applicable building codes.
  • Follow instructions and advice from your building’s safety engineers or operations staff.


Follow CDPH guidance for indoor ventilation, filtration, and air quality. Use fresh air whenever possible to help prevent COVID-19. Good ventilation will help protect individuals from COVID-19 and unhealthy air.

Further guidance is available for building operations and selecting a portable air cleaner.


Follow guidance for cleaning your facility.

Last updated March 14, 2023