Schedule rooftop, attic and outdoor jobs with NWS HeatRisk and OSHA’s water, rest and shade guidance

OSHA warns that hazardous heat can occur indoors or outdoors in any season and that new workers need time to acclimatize. NWS HeatRisk gives a 0–4 daily forecast of heat-related impact risk that dispatchers can use to move rooftop and attic work, add breaks and check on crews.

Source facts

OSHA’s heat page says hazardous heat exposure can occur indoors or outdoors and during any season if the conditions are right, not only during heat waves. It lists heavy physical activity, warm or hot conditions, lack of acclimatization and clothing that holds in body heat as risk factors, and highlights an April 10, 2026 National Emphasis Program on heat-related hazards, OSHA Directive CPL 03-00-024.

Workers who have not recently spent time in heat need time to acclimatize, and during their first few days OSHA says employers should encourage fluids, shorter shifts and frequent breaks. Supervisors can schedule work for the morning or shorter shifts with rest breaks in the shade, all supervisors and workers should at a minimum be trained on heat symptoms and first aid, and a worker with heat stroke needs immediate cooling and a 911 call.

The National Weather Service’s HeatRisk is an experimental color-numeric index forecasting the risk of heat-related impacts over a 24-hour period, weighing how unusual the heat is for the time of year and its duration, including nighttime temperatures. It is supplementary to official heat watches, warnings and advisories; level 2 (orange) affects heat-sensitive people and some industries, and level 3 (red) affects anyone without cooling or hydration.

Applicability

Use this for any crew that works outside conditioned space. HeatRisk is experimental and not supported 24/7, so treat it as a planning aid alongside official National Weather Service alerts and site conditions.

DSE recommendation

DSE recommends building a HeatRisk check into daily dispatch for every job with outdoor, rooftop or unconditioned-space work. At level 2 or higher, move roof and attic tasks to the morning, add scheduled breaks in shade or a cooled vehicle, keep water on every truck and assign a check-in partner. Give new technicians and workers returning from leave a lighter heat load for their first days, and train every supervisor to recognize heat stroke and call 911.

Verification

Record the day’s HeatRisk level on dispatch sheets for outdoor jobs and review a sample monthly during summer to confirm the schedule changed when it should have. Keep heat-illness training records for every field employee and supervisor, and review any heat-related incident or near miss at the next safety meeting.

Official references

OSHA — Heat: Working in Outdoor and Indoor Heat Environments. National Weather Service — NWS HeatRisk (experimental). Reviewed October 18, 2026.