Heat Stress

Many people are exposed to heat on some jobs, outdoors or in hot indoor environments. Operations involving high air temperatures, radiant heat sources, high humidity, direct physical contact with hot objects, or strenuous physical activities have a high potential for causing heat-related illness. Workplaces with these conditions may include iron and steel foundries, nonferrous foundries, brick-firing and ceramic plants, glass products facilities, rubber products factories, electrical utilities (particularly boiler rooms), bakeries, confectioneries, commercial kitchens, laundries, food canneries, chemical plants, mining sites, smelters, and steam tunnels.
Outdoor operations conducted in hot weather and direct sun, such as farm work, construction, oil and gas well operations, asbestos removal, landscaping, emergency response operations, and hazardous waste site activities, also increase the risk of heat-related illness in exposed workers.
Every year, thousands of workers become sick from occupational heat exposure, and some even die. These illnesses and deaths are preventable.

How do I know if it's too hot?
  • The temperature rises
  • Humidity increases
  • The sun gets stronger
  • There is no air movement
  • No controls are in place to reduce the impacts of equipment that radiates heat
  • Protective clothing or gear is worn
  • Work is strenuous

Heat IndexRisk LevelProtective Measures
Less than 91°FLower (Caution)Basic heat safety and planning
91°F to 103°FModerateImplement precautions and heighten awareness
103°F to 115°FHighAdditional precautions to protect workers
Greater than 115°FVery High to ExtremeTriggers even more aggressive protective measures