Extreme heat can be a dangerous work hazard with serious implications for worker safety. Heat stress occurs when the body's means of controlling its internal temperature starts to fail, potentially leading to severe illness or even death. With increasingly hot summers, preparing your employees for hot weather work has become a top priority for workplace safety management.
 
In this article, we’ll share insights on what heat stress looks like in the workplace along with tips to protect employees.
 

Understanding Heat Stress in the Workplace

Heat stress occurs when someone is exposed to extreme heat for too long without the ability to cool down. Humidity, physical exertion, clothing, and individual factors all play important roles in determining heat stress risk. 
 
The body normally cools itself by sweating. But when humidity is high, sweat doesn't evaporate as quickly and prevents the body from releasing heat effectively.
 
Risk factors for heat illness include age, weight, physical fitness, medications, and pre-existing medical conditions. Workers with heart disease, high blood pressure, diabetes, or those taking certain medications should take extra precautions. 
 
New workers or those returning after time away need special consideration as they haven't built up a tolerance to working in hot conditions.
 
The wet-bulb temperature, which combines the dry air temperature with humidity levels, provides a more accurate measure of heat stress risk than standard thermometer readings. Some research suggests humans may experience dangerous heat stress at wet-bulb temperatures between 86 and 88°F.
 

What Are the 5 Stages of Heat Stress?

Heat stress progresses through different stages, with symptoms increasing in severity. Here are the stages:
 
● Heat Rash: Skin irritation from excessive sweating. It often appears as red clusters of pimples or small blisters.
● Heat Cramps: Muscle pains or spasms that happen during exercise and also include heavy sweating as well as feeling weak or light-headed.
● Heat Syncope: Fainting or dizziness caused by dehydration and blood vessels dilating to cool the body. Reduces blood flow to the brain.
● Heat Exhaustion: Can happen before a heat stroke with symptoms of heavy sweating, nausea, light-headedness, rapid breathing, and a fast weak pulse. The body temperature may be elevated but typically remains below 104°F.
● Heat Stroke: Symptoms include dry skin, dizziness, and a rapid strong pulse. With heat stroke, body temperature can rise up to 106° and can be life-threatening.
 

How Can Heat Stress Be Prevented in the Workplace?

Heat stress prevention in the workplace requires a comprehensive approach combining multiple strategies. There are some that are particularly effective.
 

Implement a Heat Illness Prevention Program

Establish clear procedures for hot weather that include safe working practices and emergency protocols. Define temperature thresholds where additional precautions must be taken.
 

Heat Acclimatization

Heat acclimatization is crucial for worker safety. To ensure heat stress prevention in the workplace, allow workers to gradually build tolerance to hot conditions over 7-14 days rather than immediately exposing them to full workloads in high temperatures. 
 
Advise them to wear light weight, light-colored, and loose-fitting clothing. Have them protect themselves from the sun by wearing sunglasses, a wide-brimmed hat, and applying sunscreen.
 

Schedule Work Strategically

If possible, adjust work schedules to perform physically demanding tasks during cooler parts of the day. If that’s not possible, allow more water and shade breaks. 
 

Provide Shade and Cooling Areas

Create spaces where workers can cool down during breaks, ideally with air conditioning or effective ventilation. Electric fans make dealing with the heat more comfortable. But keep in mind that when temperatures are in the 90s, fans will not help with heat stress prevention in the workplace.
 

Provide Proper Hydration

Make cool water readily available and encourage workers to drink regularly even if they don't feel thirsty. Keep these three tips for heat stress prevention in mind:
 
1. Drink more fluids regardless of your activity level. Don’t wait until you’re thirsty.
2. Don’t drink fluids that contain large amounts of sugar.
3. Sports drinks can help replace the salt and minerals you lose when you sweat.
 

How to Avoid Overheating at Work?

For much of this article, we’ve written from the employer's perspective. But if you’re an employee, what can you personally do to practice heat stress prevention in the workplace?
 
While your employer should provide heat safety protocols in place, protecting yourself from overheating requires personal vigilance. Here are some actions you can take:
 

Know Your Personal Heat Tolerance

Everyone responds differently to heat. If you have diabetes, high blood pressure, or take certain medications, you may be more susceptible to heat stress. Be aware of your own risk factors.
 

Watch for Early Warning Signs

Overheating doesn't happen suddenly. Learn to recognize early symptoms in yourself like:
 
1. Excessive sweating or sudden lack of sweating
2. Muscle cramps or weakness
3. Headache or dizziness
4. Nausea or loss of appetite
5. Rapid heartbeat
 

Take Immediate Action

If you notice symptoms, don't wait for them to worsen. Stop working, move to shade or air conditioning, and let someone know how you're feeling. It's better to lose a few minutes of productivity than risk serious illness.
 

Use a Buddy System

Check on your coworkers regularly, not just yourself. Look for signs like confusion, irritability, or unsteady walking that they might not notice themselves.
 

Create Your Own Strategies to Keep Cool

Even without official breaks, find moments to cool down. Splash water on your face and neck, place cold water bottles against your wrists, or use wet bandanas.
 

Time Your Effort Wisely

If you have flexibility in task order, tackle the most strenuous work during the coolest parts of your shift. Save lighter tasks for peak heat hours.
 

Know When to Stop

Don't be a hero. If you feel seriously unwell, stop working immediately and seek help. Heat stroke can be fatal, and no job is worth that risk.
 

Treating Heat Stress Illnesses

Treat a person by having them rest in a cool place, have legs slightly elevated for heat stroke and exhaustion. Give them a sports drink like Gatorade® or PowerAde®, or water if sport drinks are not available. Spray the person with water to help cool them down more and massage away muscle cramps.
 
Companies conducting annual safety reviews should ensure their heat stress prevention protocols reflect current best practices. They should also address the specific needs of their workforce and working environments.