Safety Measures Construction Crews can Take to Recognize Heat Stress and Prevent Heat Injury

May 21, 2021 | Health & Safety

After the cool temperatures of spring slowly pass, the energy draining temperatures of summer will quickly descend on us. This makes heat stress and heat related injury a serious concern for anyone working outdoors, or in heat-producing environments. It is important to remember that heat is uncomfortable and can be very dangerous.

Heat related sickness affects thousands of workers every year and more than 40 have lost their lives because of it.  Unfortunately, about half of these deaths occur in the construction industry. Heat can make anyone sick, but people, who are overweight, have high blood pressure, or heart disease are at increased risk. So is anyone who takes allergy medication, decongestants, or blood pressure medication.

Heat stress can induce a series conditions and illnesses ranging from rashes and cramps to heat exhaustion, and life-threatening heat stroke. However, construction laborers are particularly vulnerable to heat stress and illnesses because of the heavy climates they work in.

Why is heat a hazard to workers?

When working in a hot environment, the body must get rid of excess heat to maintain its stable internal temperature. It is able to do this by circulating blood to the skin and through sweating.

If the air temperature is close to or warmer than normal body temperature, the process of cooling of the body becomes more difficult and the blood that is circulated to the skin cannot lose its heat. Thus, sweating becomes the main way the body cools off.  However, sweating is only effective if the humidity level is low enough to allow evaporation, and if the fluids and salts that are lost are adequately replenished.

Remember, if the body cannot get rid of excess heat, it will then store it. When this happens, the body’s core temperature rises and the heart rate will also increase. As the body continues to store heat, the person will begin to lose concentration and will have difficulty focusing on a task, may become irritable or sick, and many times will lose the desire to drink. The next stage is most often fainting and even death if the person is not cooled down.

How to know when it’s too hot:

  • Temperature rises
  • Humidity increases
  • The sun gets stronger
  • There is no air movement
  • No controls in place to reduce the heat imitated from equipment that radiates heat.
  • Over all work is strenuous in nature.

Contributing Factors of Heat Illness:          

  • Working in high temperatures and humidity, direct sun exposure and no breeze
  • Engaging in heavy physical labor
  • Wearing waterproof clothing
  • Protective clothing when it creates a microenvironment, that can trap heat close to the skin

Symptoms of Heat Exhaustion:

  • Headaches, dizziness, lightheadedness, fainting
  • Weakness and moist skin
  • Irritability or confusion
  • Upset stomach, vomiting

Symptoms of Heat stroke:

  • Dry, hot skin with no sweating
  • Confusion, loss of consciousness
  • Seizures or convulsions


What can you do to help prevent heat stress and protect workers from heat related injury?


Follow these precautions:

  • Know signs/symptoms of heat illness; monitor yourself; use a buddy system.
  • Gradually increase workloads and allow more frequent breaks for workers new to the heat or those that have been away from work to adapt to working in the heat (acclimatization).
  • Provide cool water to drink (five to seven ounces) every 15 minutes.
  • Require rest breaks in a cool and shady spot.
  • Schedule heavy work during the coolest time of the day.
  • When possible, assign work that can be done in the shade.
  • Rotate workers when working in the heat is unavoidable.
  • Suggest workers wear lightweight, light-color clothing.
  • Schedule additional rest breaks for workers who wear protective clothing and check their temperature and heart rate.

If a worker has symptoms of heat stroke:

  • Call 911
  • Move him/ her into shade
  • Provide cool drinking water, if able to drink
  • Wipe skin with cool water
  • Loosen Clothing
  • Fan with cardboard or other material

Working in extreme heat is many times unavoidable when working in construction; however it doesn’t have to be unendurable. With preemptive planning, proper training and investment in cooling systems for workers, construction laborers can work safely when temperatures are high.


Asma Bayunus

LMS Manager

For more information on safety measures you can take to protect yourself and your crews, visit the OSHA website: