University of Florida

Hydrating in Hot Environments

Outdoor work—mowing a lawn, painting a driveway, or tilling a garden—is always exhausting, especially when the sun is glaring against you and temperatures are creeping above 90°F. When working outside in the heat, we sweat to cool down, but in turn, we lose water.

Since every cell in our body needs water to function, remaining hydrated is essential to staying healthy and cool.

Heat-Related Illnesses


Dehydration happens when you lose too much water because of sweat. If you feel thirsty or have a dry mouth, then you may be dehydrated.

For every hour you work in the heat, drink at least two cups of water or a sports drink to ensure you stay hydrated.

Heat Exhaustion

If you stay dehydrated, then your body can overheat, leading to heat exhaustion.

Signs of heat exhaustion include:

  • Cramps
  • Dizziness
  • Nausea
  • Fatigue
  • Heavy sweating
  • Pale skin

If you have these symptoms, then go to a cooler place, remove unnecessary clothing, and slowly sip cool water or a sports drink. Be sure to seek medical attention if you do not recover.  

Heat Stroke

A heat stroke—the most serious heat-related illness—happens when you overheat too quickly and your body is unable to cool.

Signs of a heat stroke include:

  • Confusion or dizziness
  • Throbbing headache
  • Slurred speech
  • Chills
  • Hot, dry skin
  • High fever 

If you or someone you know is experiencing a heat stroke, then let someone else know and seek immediate medical assistance or call 911. You should also move the victim to a cool place immediately and cool him/her with an ice pack, hose, or fan.

Do not give the person anything to drink if the victim is disoriented and doesn’t remember his/her location, name, or the day of the week.

Preventing Heat-Related Illnesses

Although heat-related illnesses are serious, they can be easily prevented by staying hydrated and by being in tune with your body. To prevent heat stress, use the following tips:

  • Drink about two cups of water or a sports beverage every hour.
  • Do heavier work in the coolest parts of the day.
  • Wear light and breathable clothing—such as cotton—if possible.
  • Avoid alcohol and sugary, carbonated, and caffeinated drinks.
  • Look at your urine’s color—if it’s a dark yellow to orange color or darker, then you could be dehydrated.  
  • Always take a break at the first sign of feeling overheated.

Whether you’re a beach lifeguard, construction worker, farmer, or landscape artist, staying hydrated is essential—not only during the summer’s heat, but year round.   

Adapted and excerpted from:

J. Beatty and G. P. Kauwell, “Hydrating in Hot Working Environments” (FCS80018), UF/IFAS Family, Youth and Community Sciences Department (03/2012).

Heat Stress,” Centers for Disease Control and Prevention (rev. 06/2014).


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