As the spring season winds down and temperatures steadily rise, outdoor working conditions may feel more intense than usual. According to the Occupational Safety and Health Administration (OSHA), every year, thousands become sick while working in extreme heat or humidity, and dozens succumb to the harsh conditions. To spread awareness of jobsite heat safety, OSHA created the Heat Illness Prevention Campaign and recognizes National Heat Awareness Day each year.
Signs and symptoms of heat-related illness
OSHA reports that people with pre-existing health conditions are at higher risk of being affected by extreme heat conditions, but no one is immune. Personal risk factors also include medications, physical characteristics (i.e., age, pregnancy, and fitness level), and behavioral characteristics (i.e., alcohol or drug use and water intake).
Here are some signs of distress that can occur in extremely hot conditions:
- Heavy sweating: This symptom is more likely to go under the radar because — who doesn’t sweat in the heat? But if you’re sweating out water faster than you can replenish it, this could become an early symptom of heat-related exhaustion and illness.
- Tiredness or weakness: Feeling worn down is another symptom that could be considered typical for a day on the job — but muscle cramps, fatigue, weakness, and dizziness can indicate overheating.
- Headache or nausea: Headaches and nausea are some serious symptoms of a potential heat stroke where medical attention is needed as soon as possible.
- Abnormal behavior, slurred speech, seizures, or passing out: If you notice yourself or a fellow worker slurring their speech, behaving in unusual ways, or losing consciousness, get medical help immediately. These are the most severe symptoms of heat stroke and are indicators of a medical emergency.
(Adapted from the American Red Cross)
How to prevent heat exhaustion at work
While we can’t control the weather, we can try to prevent medical emergencies during extreme heat. Here are some OSHA heat safety steps for the jobsite:
- Ease into outdoor work. The Centers for Disease Control (CDC) emphasizes the importance of acclimatization to prevent heat-related illnesses. When the weather gets hot, don’t jump straight into a full workday outside; gradually increasing your exposure to hot temperatures will help your body adjust more safely.
- Take breaks. Give yourself time in a cool, shady location at frequent intervals for your body to recover before continuing to work in extreme heat.
- Wear clothing and gear that minimizes heat stress. There’s a variety of gear for the jobsite to help prevent symptoms of heat exhaustion before they start. Professionals can beat the heat with a variety of cooling products from Klein Tools at City Electric Supply (CES).
- Personal jobsite fan: Clamp or hang a Klein Tools Rechargeable Personal Jobsite Fan for powerful air circulation wherever you go. Get constant airflow for up to nine hours and adjust the fan cage from any angle for tight, stuffy spaces.
- Cooling cloth materials: Keep cool and soak up sweat with cooling cloth options. Sport the Klein Tools Cooling Do Rag by itself or under a hard hat to wick away sweat. Or grab a pack of Klein Tools Cooling PVA Towels to help regulate body temperature and protect from the sun’s harmful UV rays; its absorbent material stays cooler than the air around it for hours.
- Ventilated PPE: Even when you work in environments that require extra protective equipment, there are ways to stay cool. Put on the Klein Tools Premium KARBN™ Pattern Vented Full Brim Hard Hat, Class C, which has ventilation features to allow for airflow. When you need a mask, opt for the Klein Tools Reusable Face Mask w/ Replaceable Filters; the mesh material and ventilation valves keep your face cool while offering protection.
- Stay hydrated and replace salt and minerals. Drink plenty of water, and don’t forget electrolytes. When you sweat, you don’t just lose water; you also lose salt and minerals essential for basic life functioning (National Library of Medicine). Pack your hydrating drinks in the Klein Tools Backpack Cooler and Ice Pack to keep them cold for up to 30 hours.
Stay safe in hot jobsite conditions
The dangers of extreme heat can sneak up on anyone, especially when working outdoors. Remember to always listen to your body. Drink more water, even if you don’t feel thirsty. Take breaks frequently in a shady area with fans and cooling bands. If you feel light-headed or nauseous, take precautions and call for help. Be aware and stay prepared in the summer heat.
FAQs about heat illness
- What are some symptoms of heat illness?
OSHA reports that symptoms can include heavy sweating, headaches, nausea, cramps, weakness or dizziness, elevated body temperature, and more. - How hot does it have to be to potentially get heat illness?
Heat illness doesn’t happen at a specific temperature, but is determined by a combination of factors like age, fluid intake, humidity, temperature, physical exertion, clothing, sun exposure, and more. Workers should be aware of the hazards and contributing factors, listen to their body, and take proper precautions. You can also use OSHA’s Heat Stress Calculator to help determine risk. - How much water should you drink when working in extreme heat?
According to OSHA, workers should drink one cup of cool water every 20 minutes, whether or not you feel thirsty. For long stretches of time with more exertion, choose a drink with electrolytes. - What are signs of a heat-related emergency?
Abnormal thinking or behavior, slurred speech, seizures, or loss of consciousness are signs of a medical emergency (OSHA). Workers should call 911 immediately, cool the affected person with water or ice, remove unnecessary clothing, and supervise them until help arrives.
Last updated on May 26, 2026