As numerous heat records were shattered across the U.S. in the summer of 2023, it meant that people working outside were at major risk of heat-related illnesses like heat exhaustion and heat stroke. Heat illness is an invisible, but quite capable killer that’s caused dozens of fatalities and thousands of injuries over the past several years. And it is believed that those numbers are vastly underreported, as many heat-related illnesses and deaths fall outside the purview of government regulators.

Employers are responsible for protecting their crews from heat hazards, and these protective measures must be reinforced at every level of the organization. In this guide, we’ll address what steps contractors can take to safeguard the health of their crews.

Judging Heat Conditions on Site: Don’t Focus Only on the Temperature

Elevated temperatures are an obvious heat-related danger, and as such, it’s important for supervisors to keep an eye on the thermometer. But there’s more to heat risk than temperature alone, as humidity, solar exposure, and wind speed all play a role as well.

For example, heat index values factor humidity into the equation and is therefore a useful alternative to temperature alone along the Gulf Coast, where high levels of summer humidity are expected.

Some contractors now use the wet bulb globe temperature (WBGT) – a metric utilized by the U.S. military for decades – that also factors in solar exposure and wind speed. In other words, WBGT is most relevant for people working in direct sunlight.

As actual, on-the-ground heat dangers vary with humidity, sun exposure and other factors, it’s recommended that contractors use heat index values to assess field conditions.

What Does OSHA Have to Say About Heat Safety?

OSHA doesn’t have heat-specific safety regulations on the books, but employers are still held to the General Duty Clause, which requires companies to identify and protect workers from any onsite hazards.

Employers can’t use “but there’s no OSHA heat safety standard” as an excuse, in other words.

The agency does have plenty of heat safety resources to draw from, though, including informational literature and tips for employers. This includes guidance on every part of the safety planning process, which can be extremely helpful for new contractors that don’t have an emergency action plan (EAP) in place.

Here are some practical tips for mitigating dangerous summer temperatures for every phase of the project.

Before the job begins: Create a Heat Safety Plan and Raise Awareness of Heat Hazards

Before mobilization, contractors should have a firm idea of the jobsite’s layout and where heat hazards are likely to emerge. For instance, if there’s a part of the site that’s exposed to dawn-to-dusk sunlight, it may be a good idea to avoid setting up any workstations in that area.

This is the kind of thinking that should be included in the project’s Emergency Action Plan (EAP). In fact, some contractors go a step further and draft a heat-specific safety plan. Given the extreme temperatures affecting some parts of the country (the south and southeast, most notably), heat-specific plans make a lot of sense. Each EAP should include the following:

The location and nature of any heat hazards on the jobsite. While trapped heat is usually a problem for interior work areas only, they can emerge on construction sites and other exterior work environments as well.
The location of any cooling stations or any air-conditioned areas. If heat illness does occur, moving the affected worker to a cool spot with shade is critical.
An inventory and location of all heat injury resources, such as cold packs, towels, and fluids.
A set of processes that specify what to do and who to contact should someone come down with heat illness.
The contact information for any nearby emergency medical institutions.

Once this plan is established, it must be communicated to all levels of leadership and to the workers themselves. Ideally, leadership and the crew would be involved in helping put together a heat safety plan. This will ensure that everyone on the team has a clear understanding of the company’s heat safety policies. Regular training, toolbox talks, and unscheduled drills are all worthy investments to ensure maximum heat safety awareness.

This training should also address what signs and symptoms of heat illness to look for, as other workers are likely to spot them first in their coworkers. They include:

Dizziness
Confusion
Slurred speech
Headache and muscle pain
Nausea and vomiting
Loss of consciousness

Invest in Tools That Monitor Heat Levels

If your workers can keep an eye on the temperature, they’ll be more aware of the heat and more likely to observe heat safety protocols.

The right tools are essential for jobsite safety, and when it comes to heat-related dangers, one such tool is a liquid crystal thermometer, as LCTs are compact, lightweight, and offer instant information about the temperature. LCTs can be encapsulated and scaled down to fit inside TWIC cards, which can be worn on a lanyard, kept in a pocket, or tossed in the toolbox. LCTs are accurate and can also include the company’s branding or additional heat safety information.

In this way, LCTs offer double advantages in safety and cost effectiveness, as they’re inexpensive to procure at volume and give workers a highly usable tool for remaining aware of the heat.

Get Workers Acclimated to the Heat and Set Up a Cooling Station

According to OSHA, about 75 percent of all heat-related deaths occur in the first week of the job. It takes time for the body to adjust to extreme heat stress, especially for people who aren’t accustomed to the climate or strenuous activity. To avoid overloading the team early on, OSHA recommends the 20 percent rule. The idea behind this is to slowly work up to full capacity in the sun over several days.

Assuming an 8-hour workday, using the 20 percent rule, workers should only spend one hour and 40 minutes (20 percent) in the sun during their first day on the project. They can spend the rest of the day working without heat stress. Every subsequent day, add another 20 percent in the sun until they’re up to full capacity. Some workers may need a bit longer to adjust, and it’s better to be safe than sorry, so allow for that time for adequate acclimation.

At the project’s outset, this is also the time to establish a cooling station. It should remain in the shade throughout the day and always have water available. Some contractors set up tents with circulating fans for additional heat relief, and if there’s an air-conditioned room they can access while cooling, even better.

Keep Safety Personnel on High Alert, Encourage Regular Breaks and Reduce Work Intensity in High Heat

During the peak of summer, there may be no relief from dangerously hot days. Where possible, shifting work to the evening or night hours is recommended, but noise ordinances may prevent this.

When work must be done during the day, being proactive is the rule. That means doing the following:

Enforcing regular water breaks. During high activity periods, giving workers a break every 15 minutes to drink fluids is recommended. Stick to water rather than caffeinated beverages.
Cycling work teams out of the sun regularly. If possible, cycling workers between sun-exposed and shaded workstations can reduce heat stress.
Occasionally taking worker vitals to spot early signs of heat stress. This should only be done by trained medical personnel.
Keeping the contact information for any medical authorities in an easily accessible place, so it can be instantly referenced in an emergency.

In general, the point is to remain on high alert while heat indexes are at their most punishing. The faster everyone responds to severe heat illness, the better the affected worker’s chances of fully recovering.

Summer Heat Can Be Fatal, but Employers Can Keep Their Team Safe with the Right Protective Measures

While summers have always been hot, recent summers have produced deadly levels of heat. For work crews, heat illnesses can emerge suddenly and may be severe, if not deadly. But with effective planning, emergency resources, cooling equipment, and a commitment to heat awareness, employers can keep their project sites and workers safe and heat injury free.