When the weather turns warm, it's great to be active outside. But when
it gets really hot and humid, be careful.
Exercising in the heat can cause heat cramps, heat exhaustion and potentially
A few safeguards can help you avoid these problems. The
American College of Sports Medicine (ACSM) says drinking plenty of fluids, wearing the right clothes and exercising
at the right time of day are among the best ways to beat the heat.
You need to drink enough water, sports drinks or fruit juices before, during
and after exercise—even if you don't feel thirsty. Fluids help
your body perspire, which cools the skin and keeps body temperatures at
a safe level. Avoid very cold drinks because they can cause stomach cramps.
The ACSM recommends trying to drink as much fluid as you lose while exercising.
If your urine is clear or pale, you're probably drinking enough fluids.
American Council on Exercise and other experts list these additional strategies to help you stay cool:
- Reduce your workout intensity, particularly the first few times you're
in warmer temperatures. It usually takes 7 to 14 days to get acclimated.
- Take advantage of the coolest times of the day. Before 10 a.m. or after
6 p.m. is generally the best time for an outdoor workout.
- Don't overdress. Exposed skin cools faster than covered skin. Clothing
should be lightweight, light-colored and loose-fitting. A hat is a good idea.
- Use a broad-spectrum (protects against UVA and UVB rays), water-resistant
sunscreen with a sun protection factor (SPF) of 30 or higher. Apply it
15 to 30 minutes before going outside. This can help prevent a sunburn,
which limits the body's ability to cool itself. Reapply according
to the directions on the package.
Keep track of the "heat index," the temperature your body feels
when heat and humidity are combined. A heat index of 90 or higher can
be dangerous. (For a heat index chart, go to the National Weather Service
Watch for warning signs
Warning signs of a heat illness depend on how severe the problem is.
A mild heat illness (heat cramps) may cause painful cramps in the stomach, arm and leg muscles.
If you have these symptoms, stop exercising, gently stretch the affected
muscles and drink cool water or an electrolyte solution that's low in sugar.
A moderate heat illness (heat syncope or heat exhaustion) may cause weakness, fatigue, fainting, a body temperature of 104 degrees,
excessive thirst, decreased sweating, weakness, headache, frequent muscle
cramps, and nausea and vomiting. If you or someone you're with has
these signs and symptoms, the
American Academy of Orthopaedic Surgeons (AAOS) recommends the following:
- Move to a cool, shaded area.
- Remove tight clothing.
- Give fluids (if the person is conscious).
- Apply cooling measures such as a fan or ice towels if body temperature is high.
- See a doctor, particularly if the person has nausea or vomiting.
A severe heat illness (heat stroke) may cause signs and symptoms such as a core temperature greater than 104
degrees, nausea, seizures, confusion and disorientation. Unconsciousness
and coma are also possible. Heat stroke can sometimes occur without any
preceding signs or symptoms of heat illness.
Heat stroke is a medical emergency. If someone has symptoms, the AAOS recommends calling
911 and trying to cool the person by removing as much clothing as possible,
submerging them in an ice bath and putting ice packs on the armpits, groin
and neck. You should keep trying to cool the person until help arrives.