Prevent Heat Stress During the summer, the hot temperatures outside mean increased health risks for workers due to heat stress. Learn how you can work safely in the heat (181k, pdf). The Heat Stress Awareness Toolkit includes a guidebook (1.1mb, pdf), a poster (235k, pdf), and a tool (302k, pdf) to determine Humidex guidelines. Contact your Health and Safety Association for further details. Useful links about the dangers of heat exposure and how to prevent it: Ontario Government Health and Safety Guidelines for Heat Stress Heat Stress Calculator Working in Extreme Hot or Cold Temperature Conditions Working in Hot Environments - Control Measures Working in Hot Environments - Health Effects Ultraviolet Radiation in the Workplace Heat Stress Standards and Tips from the Occupational Safety and Health Administration, U.S.