Heat stroke can kill. If someone is confused, passes out or has very hot skin, call 911 now. Then start cooling them and stay with them until help arrives.
Call 911Free guide
Know the signs.
What every outdoor worker and crew boss should know: how to prevent heat illness, how to spot it and what to do. Based on OSHA and NIOSH guidance.
Six things to remember.
Water
Drink 1 cup of water every 15 to 20 minutes, even if you are not thirsty.
Rest
Take breaks to cool down. If you feel sick, stop and rest.
Shade
Rest in the shade or in a cool place.
Build up slowly
If you are new or are returning to work after time off, your body needs time to adjust to the heat.
Know the signs
If you notice signs of heat exhaustion, stop working and cool down. If you notice signs of heat stroke, call 911 immediately.
Watch out for each other
Work with a buddy and never leave a sick coworker alone.
Heat exhaustion: stop and cool down.
Signs
- Heavy sweating
- Muscle cramps
- Headache
- Dizziness
- Nausea or vomiting
- Weakness or extreme tiredness
- Cold, clammy skin
- Extreme thirst
What to do
Have the worker stop working and move to the shade or into air conditioning. Loosen their clothing. Cool them with water or wet cloths and have them sip water. Call the supervisor and stay with the worker. If the worker gets worse or does not improve, call 911.
Heat stroke: this is an emergency.
Signs
- Confusion or slurred speech
- Passing out
- Seizures
- Very hot skin (wet or dry)
- Strange behavior
What to do
Call 911 immediately. Start cooling the worker right away: soak them with cold water, put ice on their neck, armpits and groin, and fan them. Stay with the worker and give the 911 dispatcher the job site address. Do not give the worker anything to drink unless they are fully awake.
A worker with heat stroke may be too confused to ask for help. If a coworker seems confused or is acting strangely, treat it as an emergency.
Building up to the heat.
A body that isn’t used to the heat yet is at higher risk. NIOSH guidance is to start with less time in the heat and build up.
| New to the job | On the first day, limit time in the heat to no more than 20% of a normal shift. Increase that time by no more than 20% each day after that. |
|---|---|
| Returning after 1 week or more away | Limit time in the heat to 50% of a normal shift on day 1, 60% on day 2 and 80% on day 3. Return to a full shift on day 4. |
| The first 14 days | Closely monitor new workers during their first 14 days on the job. |
Check the heat every day.
The heat index combines temperature and humidity, so a humid day can be more dangerous than the thermometer shows.
Below Level 1.
The kit’s plan starts at a heat index of 80°F. Water, rest and shade still matter every day.
Level 1: Heat index of 80°F or higher.
Water and shade are set up before work begins. The crew watches for signs of heat illness. New workers are closely monitored. Any worker may rest whenever they need to.
Level 2: Heat index of 90°F or higher.
All Level 1 steps apply. In addition, workers take a rest break of at least 15 minutes every 2 hours in the shade or a cool area. The supervisor reminds the crew about heat safety. One person is assigned to watch for signs of heat illness. The heaviest work is scheduled for the coolest hours of the day.
This shows how the kit’s plan works. It is not a forecast. Check the heat index each workday with the OSHA-NIOSH Heat Safety Tool app or at weather.gov.
Before the hot day starts.
- Water: cool, clean drinking water on site, with at least 1 quart per worker for every hour worked.
- Shade: a shade or cool rest area set up before work begins.
- Address: everyone knows the job site address and nearest cross street, so a 911 call isn’t delayed.
- Cooling supplies: ice, a cooler, water and towels on site.
- A plan: who calls 911, who meets the ambulance and where the nearest emergency room is.
- No fear: workers know that if they feel sick, they can stop and call the supervisor without getting in trouble.
This guide is general safety information, not medical advice. It is based on OSHA and NIOSH guidance. If you are not sure how serious it is, call 911.