Beat the Heat with a Cool Summer Construction Safety Plan

While summer has a while to arrive, now is the time to start planning for heat safety.

• By Cindy Pauley
• Mar 14, 2025

Do you think you’ve heard it all before when it comes to heat safety for construction? You may want to think again! Did you know that the three-year average of heat-related worker deaths has doubled since the 1990’s or there may be more heat-related events than you thought?

A 2021 EPA study found that heat-related workplace illnesses and fatalities are under reported because heat is often not recognized as a contributing factor Additionally, OSHA analyzed 2021 enforcement investigation information and found that construction workers experience one of the highest fatalities rates compared to other industries —13 times the level of risk as their non-construction colleagues. Remember, as temperatures rise, so does the opportunity for serious health consequences, especially in outdoor, labor-intensive industries.

Don’t sweat – plan ahead!

Ensuring workers are safeguarded from extreme heat shouldn't be a cause for stress if you prepare in advance. So, before gearing up for another productive summer, let's delve into some essential safety tips to help your workers beat the heat!

1. Understand heat exposures

Heat exposure can affect each person differently depending upon factors such as job task, personal health, use of medications, and age. Early recognition of signs and symptoms of illness, including changes in behaviors or physical appearance, is critical for ensuring health and well-being of workers.

Heat exposure can be amplified when workers are in direct sunlight or required to work near hot objects (ovens, asphalt, etc.), or where air movement is limited. Prolonged exposure to high temperatures can lead to heat stroke, heat exhaustion, or other health emergencies that can affect a worker’s ability to operate heavy equipment or machinery safely. Overheating may also lead to dehydration, which can diminish workers' ability to think clearly or respond promptly when needed.

2. How hot is too hot?

Simply put, when a person is unable to maintain an appropriate heat exchange between their body and the environment , it’s too hot. This means workers must be able to cool themselves sufficiently to keep core body temperature down. This can vary from person to person and region to region.

Weather services, such as the National Weather Service (NWS), offer heat indexes that are useful alternatives to lengthy math equations. When the heat index exceeds 100 degrees Fahrenheit, experts label it as dangerous. Heat indexes should not be relied on exclusively, however. A comprehensive assessment of heat exposure must also consider a workers clothing and PPE, humidity, radiant heat sources, and other contributing factors.

Local or national alerts are also good threat indicators. The NWS may issue any one of the following when the Heat Index is expected to exceed 105° for at least 2 consecutive days:

• Outlooks — when the potential exists for an excessive heat event in the next 3-7 days.
• Advisories — when an excessive heat event is occurring, could happen soon, or has a likelihood of occurring and could threaten life or property.
• Watches — when the weather is favorable for an excessive heat event in the next 24 to 72 hours.
• Warnings — when a heat threat is occurring, imminent, or likely and immediate protective action is needed.

3. Develop monitoring procedures

Monitoring heat exposure is more than just keeping an eye on the weather forecast. Employers should implement additional procedures to track worker safety. Here are just a few effective and affordable options:

• Using biomonitoring which may include remote heat sensing devices, wearable technologies like watches or smart clothing, thermal cameras, or drones;
• Establishing a buddy system so workers look out for one another; or  
• Having employees self-monitor urine coloring (the clearer, the better!).

4. Acclimate workers

Acclimation means allowing individuals to gradually adjust to working in high temperatures. This is especially important for younger workers, workers with health conditions, or temporary workers not accustomed to working in the heat.

Most people adjust well within 4-14 days, especially when using OSHA’s “Rule of 20 Percent.”  This rule recommends workers perform normal work, but only for 20 percent of their normal shift on their first high-heat day, then increasing their work duration by 20 percent for each day following until reaching their normal workday.

OSHA provides an example in this letter from 2021 stating,

“If the normal workday lasts 8 hours, then new workers should work no more than 1 hour and approximately 40 minutes (20 percent of 8 hours) on their first day in the heat and spend the remainder of the workday doing work tasks without heat stress.”

5. Implement protective controls

The best protection from dangerous heat includes engineering controls, work practices, PPE, or a combination of the three.

• Engineering controls may include air cooling like misting fans, shielding from radiant heat off equipment or processes, or insulating equipment used in hot processes. Employers may also consider providing mechanical equipment to help reduce manual work or cooling seats for rest breaks as additional control options.
• Work practices may include adjusting work schedules as necessary, delaying work during dangerous temperatures, and providing additional hydration and breaks during periods of intense heat.
• PPE may include reflective garments that repel radiant heat, water-cooled clothing, or personal air-cooling systems. Clothing should be light-colored, loose-fitting, and breathable to allow heat exchange with the air.

Additionally, OSHA promotes a Water-Rest-Shade concept that includes:

• Water — drink one cup of cool water or other cool liquids every 15-20 minutes; avoiding caffeinated beverages which can increase dehydration. OSHA also recommends providing access to fluids with electrolytes for worker exposed to two or more hours of work in excessive heat.
• Rest — As the temperatures rise, so should the number of breaks employees take. Rest breaks should be at least five minutes, increasing in duration as heat exposure increases.
• Shade — Breaks should be in cool or shaded areas away from radiant heat of machines, equipment, or work processes so workers can recover appropriately.

6. Response plan for heat-related emergencies

Having a plan in place for responding to heat-related emergencies can be the difference between a rapid recovery or life-threatening event. The emergency plan should identify contact numbers for emergency response teams and the location of emergency equipment and first aid supplies.

7. Train supervisors and workers

Supervisors must understand how to monitor heat and signs of heat-related illness and be able to effectively communicate dire circumstances and protective measures to workers. Workers must be provided with information and skills to recognize and quickly respond to heat-related emergencies.

Training should include:

• Identifying dangerous heat and humidity levels;
• Recognizing signs and symptoms of heat-related illnesses;
• Responding to heat-related incidents (first aid, contacting help, etc.);
• Reporting heat-related incidents and near misses; and
• Periodic drills and training refreshers.

Safety tips or regulatory requirements?

You may have noticed the tips above resemble regulations — and you’d be correct! Although there’s not a heat stress standard, there is a current National Emphasis Program (NEP), and OSHA has a proposed rule in the works. These safety tips are designed not just to keep your construction worker safe this summer but should also help prepare you for OSHA’s proposed Heat Injury and Illness Prevention rule. The proposed rule was currently in the public comment period, which ended Jan. 14.  Now OSHA will review all comments received and conduct a comment analysis. Then the agency will decide whether and how to proceed with the rulemaking process or issue a new or modified proposal.

This article originally appeared in the February/March 2025 issue of Occupational Health & Safety.