Many people with MS experience a temporary worsening of their symptoms when the weather is very hot or humid or when they run a fever, sunbathe, get overheated from exercise, or take very hot showers or baths.
These temporary changes can result from even a very slight elevation in core body temperature (one-quarter to one-half of a degree) because an elevated temperature further impairs the ability of a demyelinated nerve to conduct electrical impulses.
Strategies for Easing the Effects of Heat
- Drink plenty of fluids - preferably cool water - throughout the day. Avoid caffeinated drinks because caffeine acts as a diuretic. Remember, by the time you feel thirsty, your body is already getting dehydrated.
- Stay in an air-conditioned environment during periods of extreme heat and humidity. The cost of an air conditioner needed to help minimize the symptoms of MS may be tax deductible if a physician has written a prescription for it.
- Wear cooling garments such as vests, headbands and neckbands during exercise or outdoor activity; be aware of the added weight of a cooling vest.
- Exercise in a cool environment, such as walking in an indoor mall or working out at an air-conditioned gym. If you typically exercise outside, pick cooler times of the day, such as early morning. As always, consult your doctor before you start any exercise program or have questions about your existing regimen.
- Exercising in cool water (80-84 degrees) is an excellent way to combat heat during physical activity.
- Try pre-cooling to decrease the heating effects of exercise and increase the time it takes for the core body temperature to rise. To pre-cool yourself, get into a bathtub of comfortably lukewarm water to start; continue adding cooler water during a period of 20-30 minutes.
- A cool bath or shower can also help reduce core body temperature following activity or exposure to a hot environment.
- A simple damp cloth or towel can be helpful if you don't have a cooling product.
- Wearing wide-brimmed hats and light-colored, loose clothing can also help.
- Icy drinks or popsicles can provide temporary relief.
- Don't overdo it, especially when you're outside in the heat. Know your own limits.
Heat-Related Symptoms are Temporary
Heat generally produces only temporary worsening of symptoms and does not cause more disease activity or demyelination or damage to the nerves themselves. The symptoms are generally rapidly reversed when the source of increased temperature is removed.
People with MS who are planning to move to a very warm climate should try to visit first; plans may have to be changed if the weather seriously worsens MS symptoms.