OSHA offers a smartphone app, available in both English and Spanish, that workers can use to calculate the heat index at their worksite. It’s called OSHA Heat Safety Tool, and it lets workers know instantly if they are in a high-risk zone due to heat and humidity. It also indicates the necessary precautions to take.

It was recently updated for iOS to be more intuitive and now includes the daily maximum temperature so that employers can plan work around the hottest part of the day, moving the most strenuous tasks to cooler hours and taking appropriate precautions when risk is highest. The new version of the iOS app offers a full screen color alert and improved navigation. The app is free and available for iPhone and Android at here.