Improved heat safety app now available

Just in time for the summer spike in temperatures comes an updated app to help employees stay safe when working outdoors in hot weather.

The free app was originally issued by OSHA and has been redesigned by OSHA and the National Institute for Occupational Safety and Health (NIOSH). The OSHA-NIOSH Heat Safety Tool mobile app is available for iOS and Android devices. It determines heat-index values, a measure for how hot it feels, based on temperature and humidity.

Workers exposed to hot and humid conditions, including construction workers, landscapers, and farmers, are encouraged to use the app to check conditions if they plan to be outdoors for short or long periods during the summer heat.

Extreme summer heat causes more deaths than any other weather-related hazard. Each year more than 65,000 people seek medical treatment for extreme heat exposure. Work-related exposure to heat can result in reduced productivity and a higher risk of injuries, like those caused by sweaty palms, foggy safety glasses, and cognitive impairment related to heat.

The app uses geolocation capabilities to pull temperature and humidity data from government satellites to determine the heat index. It shows the current risk level—minimal, low, moderate, high, or extreme—and forecasts the hourly heat index throughout the entire workday. This gives employers information they can use to adjust the work environment as needed to protect employees.

In addition to calculating the heat index, the app provides users with specific recommendations about staying cool, staying hydrated, and scheduling rest breaks. Among the recommendations:


  • Limit time in the heat and/or increase recovery time in a cool environment.
  • Increase the number of workers per task.
  • Train supervisors and workers about heat stress, including symptoms of heat-related illness, first aid, and risk factors.
  • Use a buddy system where workers observe each other for signs of heat intolerance.
  • Provide adequate amounts of cool, potable water and encourage drinking.
  • Use a heat alert program whenever the weather service predicts a heat wave.
  • Develop a plan to get employees acclimatized to hot weather and to increase physical fitness.