Extreme summer heat is increasing in the United States, and heat waves are projected to increase in frequency, intensity, and duration. Outdoor workers are particularly vulnerable to such heat, and this mobile app from the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) lets workers and supervisors plan outdoor work activities based on how hot it feels throughout the day. The app shows real-time heat index and hourly forecasts, specific to your location.

The app also displays a risk level associated with the temperature. Users can receive reminders about protective measures to protect them from heat-related illness in their current climate conditions—reminders include drinking enough fluids, scheduling rest breaks, and planning for and knowing what to do in an emergency.

The app is available in English and Spanish for Android and iPhone devices. To access the Spanish version on the iPhone, set the phone language setting to Spanish before downloading the app.

Images below show examples of the app in use. For more information about safety while working in the heat, see OSHA's heat stress webpage.