I work in a small crew with three other guys. On one 90 degree day, we were doing some emergency roadwork and my co-worker Mike was complaining about this rash and headache all morning. Someone in the crew told him to drink some water, but by mid-afternoon he was getting worse – nauseous and dizzy, on top of the pounding headache. He went home to try and rest it off. Now we know that Mike's symptoms were related to the heat, and we're always on the lookout for the warning signs so we can take care steps before things get out of hand.

What Is Heat-Related Illness?

Heat-related illness is a serious concern for anyone who works in the heat. Dozens of workers die and thousands more fall ill each year from exposure to extreme heat. While more than 40 percent of heat-related deaths occur in the construction industry, anyone working in a hot environment is vulnerable (learn more in Summertime Roadwork and Heat Stroke).

There are some factors that put workers at greater risk of heat-related illness, including:

  • High temperatures and humidity
  • Limited air flow (breeze, wind, or ventilation)
  • Direct sun exposure with no access to shade
  • Contact with hot objects or radiant heat sources
  • Physical exertion
  • Bulky, non-breathable protective clothing

Preparing for the Heat Is Key

OSHA regulations require employers to provide workplaces free of known safety hazards—and this includes extreme heat. Employers should establish a thorough safety prevention program, which may include:

  • Providing workers with water and a cool, shady area to rest
  • Modifying work schedules and allotting time for more frequent breaks
  • Training employees to recognize signs of heat-related illness
  • Ensuring workers in extreme heat are constantly monitored

Signs of Heat-Related Illness

When an employee develops a heat-related illness, responding early and quickly is critical. Make sure you and your team know how to spot the signs before things get worse.

Assess the worker and, if needed, get them medical attention if they show any of these symptoms:

  • Hot, dry skin
  • Profuse sweating
  • Elevated body temperature
  • Headache
  • Nausea
  • Dizziness or lightheadedness

Preventing Heat-Related Illnesses

Employers and employees must work together to prevent heat-related illnesses from occurring.

Employers or supervisors can contribute to prevention efforts by:

  • Allowing workers to gradually acclimatize to heat and take more frequent breaks
  • Implementing work/rest cycles and avoiding work at the hottest periods of the day
  • Providing a consistent supply of safe drinking water to keep workers hydrated (see Ergodyne's Drink to Your Health: All You Need to Know About Hydration white paper to learn more)
  • Providing workers with hats and breathable protective clothing, where possible

Employees can mitigate their risk of heat-related illness by:

  • Understanding and being able to identify signs of illness; monitoring their coworkers for these signs
  • Remaining hydrated throughout the day by drinking 5 to 7 oz. of liquid every 15 minutes
  • Eating healthy, balanced meals to ensure the body can replenish itself
  • Taking frequent breaks to prevent exhaustion and give the body time to cool down


Extreme heat is sometimes overlooked as a significant occupational health and safety risk, but it can have serious consequences. Since heat-related illness is completely preventable, it’s essential for every employer to take the time to understand and communicate the risks and warning signs to workers. Being prepared can help workers stay safe while working under the hot summer sun.