OSHA Heat Safety Tool - Get the heat index for your work site and precautions to prevent heat illness. When you're working in the heat, safety comes first. With the OSHA Heat Safety Tool, you have vital safety information available whenever and wherever you need it — right on your mobile phone. The App allows workers and supervisors to calculate the heat index for their worksite, and, based on the heat index, displays a risk level to outdoor workers. Then, with a simple tap, you can get reminders about the protective measures that should be taken at that risk level to protect workers from heat-related illness—reminders about drinking enough fluids, scheduling rest breaks, planning for and knowing what to do in an emergency, adjusting work operations, gradually building up the workload for new workers, training on heat illness signs and symptoms, and monitoring each other for signs and symptoms of heat-related illness. Stay informed and safe in the heat, check your risk level. For more information about safety while working in the heat, see OSHA’s heat illness webpage, including new online guidance about using the heat index to protect workers.