Know When to Prepare for Heat-Related Illnesses
The heat index is a good tool for determining when you should take precautions to prevent health issues and what precautions you need to take. Keep up with weather forecasts so you'll be aware when conditions can lead to health issues.
- Low level of risk: A heat index below 91 degrees Fahrenheit
- Moderate risk: A heat index between 91 and 103 degrees Fahrenheit
- High level of risk: A heat index between 103 and 115 degrees Fahrenheit
- Severe risk: A heat index that's greater than 115 degrees Fahrenheit
Heat-Related Illnesses, Symptoms and First Aid
Use the information below to help prepare for working in high-heat conditions. See the Occupational Safety and Health Administration's Heat-Related Illnesses and First Aid page for the same guidance that professional outdoor laborers use when working in hot conditions.
When working outside in a hot climate, you should:
- Have access to enough cool drinking water.
- Keep a portable cooler with you to keep drinks cool.
- Make sure you have access to appropriate medical care if needed.
Heat Exhaustion
Heat exhaustion can occur when heavy sweating removes fluid and salt from the body. Symptoms of heat exhaustion can include nausea, thirst, dizziness, weakness, headache, heavy sweating and fainting. You may notice that you're more irritable, have a decreased urine output or have an elevated body temperature.
When heat exhaustion occurs, rest in a shaded, cool location. Drink plenty of cool water and apply ice packs or cold compresses to cool down. Don't resume work the same day. If the symptoms last longer than 60 minutes or get worse, seek immediate medical attention.
Heat Stroke Symptoms
Heat stroke or sunstroke is an emergency condition that can lead to death. You may sweat excessively or have a very high body temperature. You may appear confused, lose consciousness or experience seizures. Excessive sweating and hot, dry skin are other heat stroke symptoms.
Call 911 immediately if you or someone else is exhibiting signs of heat stroke. Until help arrives, move to a cool, shaded location. Apply cool water, ice or cool compresses to the skin. You can even soak clothing in cool water to help bring your body temperature down. Drink fluids (ideally water) as quickly as possible. Remain calm until medical help arrives.
Heat Stroke and Heat Exhaustion Prevention
To reduce the risk of heat stroke or heat exhaustion, wear lightweight, loose-fitting clothing. Stay hydrated by drinking fluids regularly when you're outside in the heat. You can avoid sunburn, which makes it harder for your body to stay cool, by wearing sunscreen. Finally, plan to work outdoors earlier or later in the day — when temperatures are cooler.
Heat Stroke Versus Heat Exhaustion
Heat stroke is more serious than heat exhaustion, though both can cause similar symptoms. Heat stroke is easily identified if your body temperature exceeds 104 degrees. Heat stroke causes a rapid, strong heart rate and pulse, compared to heat exhaustion, which results in a weak but fast pulse. While fainting or lightheadedness can occur with heat exhaustion, heat stroke is more likely to cause a complete loss of consciousness.
Other Heat-Related Illnesses
Heat Cramps
Heat cramps develop as the body sweats away body salts and fluid. Cramps can occur both during the work day and after work. Get to a cool, shaded location and rest. Allow a few hours before resuming strenuous tasks. Hydrate with plenty of water. Get immediate medical attention if the cramps continue.
Sunburn
Sunburn results in painful, red skin and blisters. It can also make other heat-related illnesses more likely because it reduces the body's ability to get rid of heat. Cool cloths and aloe applied to the sunburn can provide relief. Allow the areas to heal before additional sun exposure.
Heat Rash
Heat rash is a common irritation of the skin. It can develop when sweat doesn't evaporate from the body. Keep the affected area dry.
Tips for Working in Low-Risk Heat
- Stay hydrated with water rather than caffeinated or sugary drinks. Take frequent, small sips of water to stay ahead of thirst. As a general rule, you should drink up to 4 cups of water every hour and, in most cases, no more than 6 cups per hour or 12 quarts per day. Be particularly vigilant of your hydration when working in direct sun, working on hot days, or doing work that requires physical exertion.
- Make sure you know who to call if you or someone you’re working with needs medical help. It’s important to be able to provide good directions to the location.
- Pay attention to the protective gear you’re wearing. Clothing that doesn't breathe and heavy gear call for additional measures to prevent heat-related problems. Remove the gear during breaks when possible. Monitor factors such as heart rate and body temperature to identify early signs of a heat-related illness.
- Give yourself time to acclimate after you've been out of hot working conditions for more than a week. Take breaks more often to allow yourself to adjust to high temperatures. As the heat risk rises, monitor your symptoms more closely to make sure you adapt.
- If you’re working with someone, make sure they’re aware of any conditions or potential health issues you have and know how to take protective measures. Confirm that they can recognize heat-related illnesses and know how to handle them. It can be difficult for a person to notice when they are experiencing symptoms themselves.
- Use sunscreen and wear a hat when working in direct sun. Locate shaded areas for breaks if possible.
Protecting Yourself at Higher Risk Levels
At heat index levels beyond 91 degrees Fahrenheit, take additional precautions.
Change the work as necessary for higher-risk heat levels. Plan to work at times when the heat index is lower, and slow down the pace of the work. At a heat index of 115 degrees Fahrenheit or higher, avoid any tasks that require physical exertion and those that need heavy safety equipment or clothing that doesn't breathe. Move this work to a time when the heat index is below 115 degrees Fahrenheit. Reschedule outdoor work to days when a lower heat index is forecast. If you can't reschedule the work, move it to the coolest part of the day.
Take care of yourself. Wear cooling clothing and use personal devices if you have them (e.g., a misting system), particularly if you’re wearing heavy safety gear. If protective measures are not possible or not sufficient, stop work until the risk is lower.
Other Hot Weather Hazards
Heat-related illnesses aren't the only concerns in a high-heat environment. Conditions can lead to injuries from slippery, sweaty hands, eye protection that fogs and obscures vision, and burns from hot surfaces. Gloves improve grip and protect hands from hot surfaces and vented goggles, and respirators help reduce fogging of eye protection. View our guides for common safety gear to learn more: Gloves Buying Guide, Eye Protection Buying Guide and Respiration Protection Buying Guide.