Heat stress is a serious illness that can affect employees working in high temperature areas. Exposure to extreme heat or hot environments is one of the most dangerous hazards in the workplace. We sometimes underestimate how serious it can be. But the truth is, thousands of workers are affected by heat stress every year.

Have you ever had a close call with a heat-related illness? Perhaps you’ve been in that type of situation without even realizing it. Maybe you worked outside all day in hot, humid temperatures. And you pushed through the pain and discomfort. You might have gotten lucky. Heat stress can sneak up on you. No matter what kind of environment you work in.

Where do your employees do their work? Are they outside during hot summer months? Even if they work indoors they can be at risk. It’s not uncommon for heat stress to occur in places like foundries, factories, and other operations that use high temperature equipment.

Radiant heat sources, high humidity, and strenuous physical activity also have the potential for causing heat stress.

OSHA requires employers to provide safe work environments for their employees. And while you can’t control the weather, you can implement policies and procedures for reducing the risk of heat stress. First, let’s take a closer look at what heat stress is.

What is Heat Stress

Heat stress takes place when the human body is no longer able to maintain its normal temperature. Heat stress can result in a number of different heat-related illnesses. The most common ones are heat cramps, heat exhaustion, and heat stroke.

Train yourself and your employees to recognize the signs and symptoms of each of these illnesses. The information found below are current recommendations from the Center for Disease Control and Prevention (CDC).

Heat Cramps

Although heat-related illnesses do not always progress from one to another, heat cramps are usually the first form of heat stress that a person will experience. It affects workers who sweat a lot during strenuous physical activity.

Sweating depletes the salt and moisture levels from a person’s body. Low salt levels can cause painful cramping of the muscles.

Signs and Symptoms: Muscle cramps, pain, or spasms in the arms and legs.

Treatment: Drink plenty of water. Replace electrolyte loss with sports drinks every 15-20 minutes. Eat a snack that has extra carbohydrates. Seek medical help if the cramps do not subside within one hour, or if the person has a low-sodium diet or a heart condition.

Heat Exhaustion

Heat Exhaustion is more serious than heat cramps. It’s the next stage of heat stress. Heat exhaustion occurs when profuse and excess sweating continues to take place. A victim of heat exhaustion has experienced major water loss. If left unaddressed, it could lead to a heat stroke.

Signs and Symptoms: Headache, nausea, dizziness, irritability, thirst, heavy sweating, and elevated body temperature (greater than 100°F).

Treatment: Seek medical help. Remove the worker from the hot area. Give the person liquids to drink while waiting for medical care. Remove any unnecessary clothing, including socks and shoes. Cool the worker with cold water and/or ice packs to the head, neck, and face.

Heat Stroke

Heat stroke is the most serious heat-related illness. It happens after the body’s temperature regulating system has failed. Heat stroke occurs when the worker’s temperature rises to a critical level (above 104°F). 

At this point, you have a major medical emergency on your hands. Heat stroke could quickly result in the death of an employee.

Signs and Symptoms: Confusion, slurred speech, loss of consciousness, and seizures. The victim may also have stopped sweating. That’s because the sweating mechanism has failed, and the body is no longer able to cool itself.

Treatment: Call 911. Emergency medical care is needed as soon as possible. Move the worker to a shaded, cool area. Remove outer clothing. Cool the worker quickly with cold water or an ice bath if possible. Circulate the air around the worker with a fan if available. Place cold cloths or ice packs on the head, neck, armpits, and groin.

Historical Data

According to the CDC, over 600 people die from extreme heat every year. That number includes people of all ages, and occurs both at home and at work. Your employees should take what they learn from work and apply it at home, too. They can protect themselves and their families with the knowledge that you give them.

The U.S. Office of Compliance recently submitted a report on work-related heat stress incidents. The reports indicates 38 workplace fatalities occurred in 2013. It also indicates that in the same year, 16,320 workers suffered from heat-related illnesses that caused them to miss work.

These deaths and illnesses are preventable. Take the necessary steps to avoid these incidents at your workplace.

Preventing Heat Stress

The best way to prevent heat stress is through hazard recognition. Identify potential heat hazards in your workplace. Evaluate the work your employees do. Determine which jobs have the highest risk of developing heat stress.

Review your indoor and outdoor operations. Below are two lists of common industries whose employees risk exposure to heat-related illnesses.

Indoor Operations

• Iron and Steel Foundries
• Non-Ferrous Foundries
• Ceramic Plants
• Glass Production Facilities
• Commercial Kitchens
• Chemical Plants
• Structural Firefighting
• Mining Sites
• Smelters
• Steam Tunnels
• Boiler Rooms

Outdoor Operations

• Farming
• Construction
• Oil and Gas
• Wildland Firefighting
• Hazardous Waste Sites

Some workers are at greater risk than others, based on their personal factors. That includes anyone over the age of 65, is verweight, has high blood pressure or heart disease, or takes medication that could be affected by high temperatures.

You should also implement a Heat-Illness Prevention Program. Key elements of this kind of program include:

• Training
• Modified Work Schedules
• Water, Rest, and Shade
• Monitoring for Signs and Symptoms
• Emergency Planning and Response

Training

Train your workers on the hazards of heat stress. They should be able to recognize the signs and symptoms. They should also understand how to respond in an emergency. Train them on the specific work practices you have in place to prevent heat stress.

Modified Work Schedules

Schedule outdoor work and physically demanding work strategically. This type of work should be done during cooler times of the day. If possible, schedule outdoor work when there is a reduced heat index. You can also rotate workers and split shifts. Implement work/rest cycles. Stop all work if the risk of heat illness is too high.

Water, Rest, and Shade

Similarly, employees should be getting plenty of water, rest, and shade. Cool drinking water should be readily available. Fully-shaded or air-conditioned areas are ideal for breaks and rest periods. Water, rest, and shade might not be enough. You may want to consider providing personal protective equipment like cooling vests and headbands.

Monitoring for Signs and Symptoms

Encourage your employees to use the “buddy system.” Designate employees and supervisors to keep an eye on specific co-workers. They can observe each other for signs and symptoms of heat stress. Employees can also monitor environmental conditions. An increase in temperature and/or humidity is a sign that heat stress could affect their crew.

Emergency Planning and Response

It’s important to have a plan in place. When an emergency occurs, you don’t want to be scrambling to figure out what to do. Be prepared. Communicate the plan to your supervisors and employees. They should know what to do, who to contact, and how to administer basic first aid when necessary.

More Information

The key elements of a Heat-Illness Prevention Program will help you and your employees better prepare against the hazards of heat stress. It could prevent heat stress from occurring at your workplace.

Heat stress can vary from minor muscle cramps to life-threatening heat stroke. Make sure you understand the various types of heat-related illnesses. Train your workers to recognize the signs and symptoms. Implement policies and procedures that will protect your employees.

Keep them cool, and keep them safe.

For more information, OSHA has a helpful FactSheet on Protecting Workers From the Effects of Heat. Chapter 6 of the CDC’s Occupational Exposure to Heat and Hot Environments also gives suggestions on how to prevent and control heat stress.

And, as always we are right here if you need us. Let us know how we can help keep your workers cool and safe.