This week, outdoor temperatures are expected to rise above 85°F, which requires University units to implement safety measures for outdoor workers to prevent heat related illness. The safety requirements are summarized on the EH&S Outdoor Heat Exposure webpage, which include training for personnel and implementing an Outdoor Heat Exposure Prevention Plan, among other requirements. Please note the L&I regulations have been updated and will be effective July 17th.  

University units and departments with personnel working outdoors are required take the following measures to prevent heat-related illness:

Heatstroke road sign

1. Ensure personnel complete the EH&S Outdoor Heat Safety training.

2. Develop and implement an Outdoor Heat Exposure Prevention Plan.

3. Ensure there is enough cool water available so that each worker is able to drink at least a quart (about one liter) every hour.

4. Enough shade is available to fully cover workers during a break, or employers can use alternatives to shade like an air-conditioned break area.

5. Allow and encourage workers to take paid cool-down breaks:

  • For 10 minutes every 2 hours when temperatures are at or above 90°F
  • for 15 minutes every hour hen temperatures are at or above 100°F

6. Implement worker observation and communication methods to detect and respond to signs or symptoms of heat illness.

For people working in hot environments, both temperature and humidity affect how hot you may feel. The higher the air temperature and percent humidity, the hotter the weather feels; your sweat is unable to readily evaporate and can’t aid in cooling your body down. Excessive exposure to heat can cause a range of heat-related illnesses from less serious heat rash and heat cramps to more serious heat exhaustion and heat stroke. Fortunately, there are measures you and your unit can take to prevent these heat-related illnesses, some of which are required by regulations protecting employee health.

For indoor workers, the EH&S indoor air quality website provides guidance for staying comfortable indoors during periods of high heat. When temperatures exceed 80°F indoors, unit supervisors or administrators should evaluate when and how to alter work practices, if needed. Units should consider the type of work, the local working conditions, and an individual’s personal response to the heat.

Contact the EH&S Air Quality team at or 206.543.7388 with questions.