NIOSH and OSHA recently released the redesigned, co-branded OSHA-NIOSH Heat Safety Tool app, which is intended to help users plan outdoor work activities based on how hot it feels throughout the day. The new version of the app replaces the one previously created by OSHA in 2011 and provides users with real-time heat index and hourly forecasts specific to their current geographical location. Based on the calculated heat index, the app also provides precautionary recommendations specific to heat index-associated risk levels that workers and managers can use to work safely outdoors. The recommendations in the app have been updated to reflect information found in the NIOSH , which the agency published in 2016 to address the hazards of heat and hot environments. An in the April 2016 authored by Brenda Jacklitsch, MS, a health scientist with the NIOSH Education and Information Division, discusses NIOSH’s updated guidance on protecting workers in hot environments. Other features of the app include editable location, temperature, and humidity controls for calculation of variable conditions and easy access to signs, symptoms, and first aid information for heat-related illnesses. “Since workers in hot environments experience heat stress from a combination of environmental factors and metabolic heat from the tasks they are performing, OSHA modified some of the heat index cutoffs to create heat index-associated protective measures for worksites,” Jacklitsch explains in a blog post about the new app. The OSHA-NIOSH Heat Safety Tool app is available to download via NIOSH’s .