Symptom Awareness

Heat Sensitivity

During the hot summer months most people complain about feeling tired and listless. But for individuals with heat-sensitive MS, staying cool in the heat is a necessity. Studies have shown that nerves with damaged myelin are sensitive to changes in temperature. A rise in temperature may cause the body not to transmit necessary signals from the brain to the body and a reduction in temperature may allow more signals to be carried across the damaged nerve. Excessive heat sensitivity can cause symptoms to temporarily worsen, including cognition and motor function.

"When your body temperature rises, the impulses cannot pass easily through the nerves affected by MS. This may cause you to feel more tired and fatigued," says Stacey Sjoquist, a physical therapist with the Franciscan Skemp/Mayo Health System Holmen Clinic in Holmen, Wisconsin.

To follow are some important tips:

Rethink your routine. During the warm months exercise or run errands early in the morning or later in the evening when temperatures are at their coolest.

Be aware of your body temperature. According to Ms. Sjoquist, body temperature is usually lower in the morning and higher in the late afternoon.

Be prepared. The best defense against heat sensitivity is a good offense. Visit www.weather.com daily during the warm summer months to check your local area's heat index. For a description of the heat index and how it impacts health, please visit www.nsis.org/weather/heatindex.html. To find out what the heat index is in your area, visit www.wunderground.com/US/Region/US/HeatIndex.html

Television weather forecasts often show when the heat index has reached a dangerous level. What level of heat may be tolerated varies from one person to another, so speak with your physician about the heat index and when you should take extra care. If the heat index is too high, try to stay indoors with air-conditioning or fans.

The Humidity/Thermometer Stopwatch is a handy device that measures temperature along with humidity and calculates the heat index. When the heat index is too high, the watch sounds an alarm. This product is available from Extech Instruments Corporation (not affiliated with MSAA) for $39.95. Interested readers may go to http://www.extech.com/instrument/products/alpha/HW30Humidity.html or call (781) 890-7440 for more information.

Watch the humidity. "Remember, the humidity can be as draining as the heat. Even if it doesn't feel very hot but it's humid, you should be very careful and take it as easy as possible," says Adam Roberts, director of MSAA's South-Central Regional Office in Mesquite, Texas.

Drink enough water. To properly hydrate and to keep your body temperature as low as possible, experts generally recommend drinking six to eight, eight-ounce glasses of water each day. Individuals should check with their own physician regarding how much water is advised for them specifically.

Use cooling devices. Both "active" cooling garments called cool suits, also known as liquid-cooled garments, and "passive" cooling garments, which include bandanas, skullcaps, and vests, can greatly help people with MS by lowering their body temperature to provide temporary symptom relief. While reducing heat sensitivity, cooling devices have been shown to temporarily help energy level, cognitive processing, and motor function.

Developed with the help of NASA, cool suits work by pumping a cool liquid through a network of small tubes sewn inside of the garment. These tubes of cool liquid help to remove heat and cool the body. Passive cooling garments do not contain an active cooling mechanism. Rather, they work via the transfer of heat by wearing a hat or other piece of clothing that contains a cooling source.

"You can make use of different cooling devices depending on your personal circumstances. You don't need to choose just one," notes Linda A. Lucuski, MPT, an administrator/physical therapist at Magee-MossRebab at Voorhees in Voorhees, New Jersey. "For example, a lightweight passive vest for riding in the car may be sufficient, but an active cooling garment could be better for a picnic on a hot summer afternoon. The most suitable cooling garment depends on a number of factors including the air temperature, your level of physical activity, and your personal sensitivity to heat."

People with MS also should consider using the cool suit for short periods of time, says Roberts. "It can be extremely advantageous. For example, wear your cool suit while doing housework."

Don't overexert yourself. If you must exercise on hot days, only do so under your physician's supervision and go easy with your workout. A better choice (again under a doctor's supervision), is to exercise in water. You'll stay cool and reap the benefits of aerobic exercise in relieving symptoms. For more information, see Health & Wellness on page 50.

Stay in an air conditioned area. According to Roberts, even in the hot, humid, southern states, some individuals with MS do not have air conditioning in their homes. To beat the heat, he advises them to run cool water over their wrists, keep their heads covered when out in the sun, and keep fans running continuously. "It's also a good idea to rest whenever you can," he says.

A former editor of The Motivator, Christine Norris is now a freelance writer specializing in health and wellness issues.

For information on MSAA's Cooling Program that offers the free use of cooling garments, please call (800) 532-7667. When calling, readers may request a copy of MSAA's Multiple Sclerosis and Cooling. This booklet may also be viewed or downloaded from MSAA's website at www.msassociation.org

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