Heat waves are uncomfortable for everyone — and downright dangerous for those who work in the sun. Each summer thousands of outdoor workers experience heat exhaustion, which if untreated can turn into heat stroke, a potentially fatal condition.
Normally, the human "coolant" system uses perspiration and blood vessels to regulate body temperature. However, when someone is working hard in the heat, especially when it's also humid, this system can break down. The result can include higher body temperature, an elevated heart rate (which can increase the risk of a heart attack), and impaired brain function that makes people more likely to overlook hazards or make mistakes.
To help employers and employees cope with excessive heat, federal and weather agencies issue heat alerts that include worker-safety precautions summarized by the slogan "water, rest, and shade." These alerts and guidance help workplaces plan for high-heat conditions and protect outdoor workers.
For additional practical workplace guidance, see Coping with Heat and Humidity in the Workplace.
To help your outdoor workers stay safe and healthy on jobs that expose them to heat, OSHA recommends that managers follow these guidelines:
Employer recommendations
- Provide heat stress training to workers and supervisors.
- Manage work activities and match them to employees' physical condition.
- Emphasize that workers should take a break, drink some water, and rest for a few minutes in a cool place at the first sign of heat stress.
Worker guidance
- Build up your tolerance for working in the heat; tolerance is normally established over one to two weeks.
- Drink a glass of water every 15 to 30 minutes while working to replace lost body fluid and help prevent overheating.
- Take breaks to cool down — a 10- to 15-minute break every two hours can be effective in very hot conditions.
- Adapt your work and pace to the weather.
- Be aware of any health conditions affected by heat and read medication labels for possible heat-related side effects.
Additional safety and heating guidance is available at Understanding Heating Safety and Heat Illness Prevention.
If you need help reviewing insurance options or coverage related to worker safety, talk to an agent.
Frequently Asked Questions
What are early signs of heat-related illness?
Early signs include heavy sweating, weakness, dizziness, headache, and nausea; prompt cooling and hydration are important.
How often should workers drink water while working in the heat?
Workers should aim to drink a glass of water every 15 to 30 minutes while active in hot conditions.
How long does it take to build tolerance to heat?
Most people develop heat tolerance over one to two weeks of gradual exposure and adjusted work-rest schedules.