Workdays spent outdoors in the heat and humidity are a fact of life for many construction laborers. But in some circumstances, these conditions can lead to heat-related illnesses, including heat stress and heat stroke, which can be fatal. Hot, muggy weather can also exacerbate other pre-existing medical conditions like cardiovascular and respiratory diseases, which can also result in death. Between the United States and Canada, nearly 1,000 deaths are linked to environmental heat exposures every year.
“The physical demands of construction combined with the need for hard hats, reflective vests and personal protective equipment like respirators and Tyvek suits can make construction workers especially vulnerable in high heat environments,” says LHSFNA Management Co-Chairman Noel C. Borck. “Dangerous exposures can also occur indoors when work involves radiant heat sources and direct physical contact with hot objects.”
What Does Heat Do?
Normal body temperature ranges between 97.8°F-99°F. When working in a hot environment, the body must get rid of excess heat to maintain a stable internal temperature. It does this through circulating blood to the skin, where it can be cooled, and through sweating. When the air temperature is close to or warmer than normal body temperature, cooling the body becomes more difficult. Blood circulated to the skin cannot lose its heat. Sweating then becomes the main way the body cools off, but for it to be effective, the humidity level must be low enough to allow evaporation and the fluids and salts that are lost must be replaced.
If the body cannot get rid of excess heat, core temperature rises and heart rate increases. As body temperature continues to rise, the person begins to lose concentration and has difficulty focusing. They may also become irritable or sick and lose the desire to drink. If the person is not cooled down, the next stage is most often fainting, followed by heat stroke, which can be deadly. Exposure to extreme heat (temperatures greater than 95°F or a combination of heat and humidity) can make this even more likely and cause it to occur more quickly.
Symptoms of heat stress include:
- Headaches, dizziness, lightheadedness, fainting
- Clammy skin
- Irritability or confusion
- Upset stomach, vomiting
Symptoms of heat stroke include:
- Dry, hot skin with no sweating
- Confusion, loss of consciousness
- Seizures or convulsions
Employers can help protect workers from extreme heat by:
- Allowing workers to acclimatize by gradually increasing exposure to heat over a two-week period.
- Providing cool water to drink and encouraging workers to drink five to seven ounces every 15 minutes.
- Requiring rest breaks in a cool, shady spot with fans and scheduling additional rest breaks and checking temperatures and heart rates for workers wearing protective clothing.
- When possible, scheduling heavy work during the coolest time of the day.
- When possible, assigning work that can be done in the shade or erecting structures to provide shade.
- Rotating workers when working in the heat is unavoidable.
- Suggesting workers wear lightweight, light-colored clothing.
- Making sure workers recognize the symptoms of heat stroke in a colleague and know what to do:
- Call 911
- Move worker to shade
- Wipe skin with cool water
- Loosen clothing
- Fan with cardboard or other material
The LHSFNA’s Preventing Heat Stress in Construction pamphlet and Heat Stress in Construction Health Alert provide additional information on how to protect workers from heat-related illnesses. These and other useful materials are available through the Fund’s online Publications Catalogue.
For information about creating an effective heat illness prevention program for your site, contact the LHSFNA’s Occupational Safety and Health Division at 202-628-5465.
LIUNA District Councils, Local Unions and signatory contractors can visit the Fund’s Sun Sense Plus page to order educational materials and products that can help protect LIUNA members from heat-related illnesses and skin cancer.
OSHA’s Heat Stress Campaign and California OSHA’s Heat Standard also provide information that can help keep construction workers across the U.S. and Canada safe. The LHSFNA recommends all employers use this information to protect their workers from the heat.
[Janet Lubman Rathner]