Exercising in the Heat
To Avoid Heat-related Conditions:

Drink enough fluids. Your body’s ability to sweat and cool down depends on adequate
rehydration. During heavy exercise in the heat, you can loose almost 2 quarts of water every
hour. Recommended fluids include water, sports drinks, and diluted fruit juices. Avoid
caffeinated beverages such as coffee, tea, and cola, which speed the excretion of water from
your body.
Sports drinks include electrolytes---sodium, chloride, and potassium---which are lost through
sweating. If you are going to be exercising very intensely or for longer than one hour, you
may benefit from fluids containing carbohydrates and electrolytes. Keep in mind that you
cannot rely on your thirst to signal how much fluid you need to drink. Your thirst mechanism
underestimates fluid loss in the heat.

Wear light-colored, loose-fitting clothing made of breathable fabric.
Dark or non-porous material can increase your temperature and
reduce evaporation. Clothing made with polypropylene can help wick
moisture away from the skin. Avoid heavy, rubberized clothing, which
can be dangerous in any weather. Loose-fitting clothing lets more air
pass over your body, providing for sweat evaporation and cooling. A
light-colored hat or cap can limit your exposure to the sun.

Exercise in the early morning or late evening. These are cooler times. If possible, exercise in
the shade.

Wear sunscreen and lip balm with a sun protection factor (SPF) of 15 or higher. Sunburn
decreases your body’s ability to cool itself.

Allow yourself time to get used to higher temperatures. Your body will gradually adapt to
Wellness Center
2100 Harrisburg Pike, Lancaster PA
|
(717) 544-3138 Phone
|
(717) 544-3139 Fax
|
www.LancasterGeneralHealth.org
the heat, allowing you to exercise with a lower heart rate and lower
body temperature. If you are reasonably fit, allow four to five days to
get used to higher temperatures. If you live with a chronic health
condition or are older, you may need 10 to 12 days to adjust. Shorten
the length of your next exercise routine, lower the intensity, and
gradually increase your effort.

Talk to your doctor if you have a chronic medical condition or take medications. Find out if
your condition or medication might affect your ability to work out in hot weather. Certain
medications, such as diuretics and antihistamines, may make you more susceptible to heatrelated illness.
Heat Related Illnesses

Mild: Heat Cramps—core body temperature stays at 98.6 degrees F.
Signs and Symptoms include: sweating, painful muscle spasms, tiny red
bumps on your skin and a prickling sensation, dizzy, weakness.

Moderate: Heat Exhaustion—core body temperature may rise to 101 degrees
F.
Signs and Symptoms include: sweating, moist skin that feels cold, weakness, nausea, rapid
and/or weak pulse.

Severe: Heat Stroke—core body temperature may rise to 105 degrees F or more.
Heat stroke is a serious, life-threatening medical emergency!
Signs and Symptoms include: absence of sweating, dry skin that feels hot, rapid breathing
and pulse, nausea, confusion/delirium, convulsions.
Have a Backup Plan
It is always a good idea to have a backup plan when the temperature soars. On days when the
heat and humidity are high, avoiding the heat altogether and exercising inside may be your
safest option. Indoor alternatives include exercising at the gym, swimming, mall walking, or
perhaps climbing stairs inside an air conditioned building.
For more information visit:
American College of Sports Medicine at www.acsm.org
American Council on Exercise at www.acefitness.org
Centers for Disease Control and Prevention at www.cdc.gov
References and Resources:
1.
Mayo Foundation for Medical Education and Research. Summertime Sports and Exercise.
www.mayoclinic.com/health/exercise.
2.
The StayWell Company: 2006.
Updated 01/07