Keeping Employees Safe When Temperatures Rise
In South Carolina, heat stress isn’t just a problem for the height of summer alone — it can sneak up as early as spring and linger well into fall. According to the Occupational Safety and Health Administration, heat is one of the leading causes of weather-related deaths in the workplace, and outdoor employees are especially vulnerable. The National Weather Service reported 177 deaths related to heat in 2024.
The good news is that most heat-related illnesses are preventable with planning and training.
What’s the risk?
When the body can’t cool itself fast enough, heat stress sets in. Factors like high temperatures, humidity, direct sun, heavy physical labor and bulky personal protective equipment, or PPE, can all push employees toward heat exhaustion — or worse, heat stroke. The National Safety Council emphasizes that even “moderate” temperatures can be dangerous when combined with physical exertion.
One of the biggest risk factors for heat illness is lack of acclimatization. Employees who haven’t recently worked in hot conditions — new hires, returning employees or those coming off extended leave — are at higher risk. OSHA and the National Institute for Occupational Safety and Health recommend gradually building heat exposure over seven to 14 days, starting with shorter work periods and increasing duration and intensity over time.
Supervisors should remember several key points:
- Everyone acclimatizes to heat differently — there is no one-size-fits-all approach.
- Age, physical condition, medications and hydration all matter.
- Yesterday’s heat tolerance doesn’t guarantee today’s safety.
Know the warning signs
Training employees to recognize heat-related illness can save lives. There are several early symptoms to watch for:
- Headache
- Dizziness or lightheadedness
- Nausea
- Heavy sweating
- Fatigue or weakness
Employees experiencing symptoms should stop working immediately, move to shade or air conditioning, loosen clothing, drink water and notify a supervisor.
A heat stroke is a medical emergency, which has important warning signs including confusion, disorientation, loss of consciousness or a body temperature of 104 degrees Fahrenheit or higher. A key red flag indicating a heat stroke is that the body may stop sweating. In cases of suspected heat stroke, it’s important to call 911 immediately.
Clothing and PPE matters
Light-colored, loose-fitting, moisture-wicking clothing can help the body cool itself. Wide-brim hats and sunscreen reduce sun exposure.
Safety always needs to come first — certain jobs, such as firefighting, electrical or welding, require specialized PPE that may increase heat stress, making work/rest cycles and hydration even more critical.
Plan ahead to protect workers
Whether employees are repairing water lines, directing traffic, maintaining parks or working around treatment facilities, heat hazards should be part of daily job planning.
OSHA and the National Safety Council have several recommendations to keep workers protected:
- Water – Encourage frequent hydration of about one cup every 10 to 15 minutes.
- Rest – Schedule regular breaks in shade or air-conditioned spaces.
- Shade – Use tents, vehicles, or temporary structures whenever possible.
- Timing – Schedule strenuous tasks during cooler parts of the day.
- Monitoring – Use weather and heat-index apps to anticipate high-risk days.
Supervisors play a key role in setting expectations and creating a culture of staying safe in the heat. When leaders model hydration, take breaks seriously, and speak up about heat risks, employees are far more likely to do the same. Heat illness prevention works best when it’s built into the organization’s safety culture as opposed to a seasonal reminder. OSHA encourages employers to train employees annually, review heat-related incidents and adjust controls as conditions change.
Login to the Municipal Association’s website to view the Preventing Heat Stress Safety Talk. For more information on heat stress or any other safety topic, contact Loss Control staff at losscontrol@masc.sc.