Between 60 and 80% of people with Multiple Sclerosis are sensitive to environmental heat. Heat sensitivity is caused by plaques on nerves where demyelination has taken place. These plaques slow the ability of the nerves to function, and heat further slows down nerve impulse transmission in demylinated regions. Some people notice that their vision becomes blurred when they get overheated—a phenomenon known as Uhthoff's sign. Heat sensitivity 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.
It is important to remember that heat generally produces only temporary worsening of symptoms and does not cause more disease activity (demyelination or damage to the nerves themselves). The symptoms reverse promptly when the source of increased temperature is removed, although under certain conditions such as infections the worsening may be more prolonged.
Heat sensitivity may be caused by things such as:
(Source: http://www.va.gov/MS/articles/Keep_Cool_Multiple_Sclerosis_and_Heat_Tolerance.asp)
It is important to remember that heat generally produces only temporary worsening of symptoms and does not cause more disease activity (demyelination or damage to the nerves themselves). The symptoms reverse promptly when the source of increased temperature is removed, although under certain conditions such as infections the worsening may be more prolonged.
Heat sensitivity may be caused by things such as:
- Working around your home (meal preparation, cleaning the house, or working outdoors)
- Taking a hot shower
- Swimming in a warm pool
- Being out in the sun or in hot/humid weather
- Physical activity, such as when walking, propelling your wheelchair, exercising, or doing other activities.
- Wearing clothing that keeps you too warm, or being in rooms that are very warm
- Medical illnesses such as bladder infections, colds, and/or the flu might cause you to experience a low to medium grade fever, which in turn increases your core body temperature.
(Source: http://www.va.gov/MS/articles/Keep_Cool_Multiple_Sclerosis_and_Heat_Tolerance.asp)
Strategies for managing the effects of heat:
Sources:
http://www.nationalmssociety.org/about-multiple-sclerosis/what-we-know-about-ms/treatments/exacerbations/heattemperature-sensitivity/index.aspx
http://www.va.gov/MS/articles/Keep_Cool_Multiple_Sclerosis_and_Heat_Tolerance.aspx
Click on the youtube video below for a Webinar on Cooling Techniques and Devices (TIP: to skip over introductions, etc. and get right to the information, scroll to 4:07 in the video)
- Use an air conditioner or fan in the room you are working in, or in your vehicle when traveling [If an air conditioner is needed to help minimize the symptoms of MS, the cost of this equipment may be tax deductible if the physician has written a prescription for it.]
- Rest in rooms that are out of direct sunlight or have adequate shading over windows that have a West or Southern exposure
- When showering or bathing, turn the fan on in the bathroom and/or open a window if possible to help circulate the room air
- Make sure the water temperature in your shower or bathtub is significantly lower than your body temperature
- Take a cool bath
- Wear layered clothing that can be removed as necessary to adjust your body temperature
- Avoid traveling to warm parts of the country or world during their hot and/or humid seasons
- When you feel hot, use a spray bottle to mist yourself with water at regular intervals during activity (or even when sitting) – as many people with MS lose the ability to perspire and release body heat
- Drink plenty of fluids:
- Place a plastic bottle of water in the freezer until frozen. Place this by your bedside at night to have cold water available to drink without having to get out of bed.
- Drink chilled water, juices, ices, and popsicles throughout the day to help keep your body temperature down.
- Avoid drinks with caffeine (e.g. Sodas, colas, coffee, tea, chocolate, and some energy drinks) are diuretics, so you lose fluid by increased urination. This leaves less fluid in your body to sweat (one of our natural ways of cooling down).
- Use cooling products (vests, neck wraps, bandanas, etc.) during exercise or outdoor activity, or pre- and post-cool
- Wear lightweight, loose, “breathe-able” clothing
- Use an oscillating fan during indoor exercise
- Exercise in a cool pool (<85 degrees)
- Use an umbrella while out in the sun.
- Wear a vented hat and sunglasses
- Take a cool bath before working around the house or in the garden
- Avoid hot or heavy meals especially before going outside
- Stay inside during the midday warmer hours
- Take a shower in a swimsuit before working outside in it (the moisture in your suit will help cool you)
- Exercise or complete home management activities in the morning (during the cool time of the day)
Sources:
http://www.nationalmssociety.org/about-multiple-sclerosis/what-we-know-about-ms/treatments/exacerbations/heattemperature-sensitivity/index.aspx
http://www.va.gov/MS/articles/Keep_Cool_Multiple_Sclerosis_and_Heat_Tolerance.aspx
Click on the youtube video below for a Webinar on Cooling Techniques and Devices (TIP: to skip over introductions, etc. and get right to the information, scroll to 4:07 in the video)
What products/services should I consider to manage this symptom?
You can contact the National MS Society at 1-800-344-4867 for a list of approved cooling product vendors or click on the this link for cooling products recommended by the MS Association of America.
http://www.mymsaa.org/msaa-help/cooling/
Other Good Resources
For more information on heat sensitivity and some recommended cooling products, click on this link: http://mymsaa.org/publications/motivator/summer-07/symptom-awareness/
Cooling Vests
The above strategies work well for most people, but this doesn’t mean that you will never have problems maintaining your body core temperature. When the “low-tech” methods (above) aren’t adequate, a cooling vest might meet your needs.
How does a cooling vest work? A cooling vest is designed to keep the body’s core temperature (around the heart and spinal cord) within safe levels to reduce symptoms of heat intolerance. The vest absorbs body heat, evaporates perspiration, and conducts cooler temperatures to the body through the skin. Cold packs for the neck, wrists and head conduct cold through to the arteries, cooling the blood circulating in the body.
When should I wear a cooling vest? The cooling vest should be worn in warm-to-hot conditions or when physical activity is planned. The vest can help keep you cool up to 3 hours when worn correctly, although this can depend on things such as environmental temperature, humidity, and your level of activity.
How do I use the cooling vest? It is beneficial to wear the cooling vest at least 30 minutes prior to physical activity. The cooling vest is more effective when worn over thin clothing and, when needed, when breathable fabrics are worn over the vest.
You will need to experiment to determine which level of cooling you can tolerate and is most beneficial to you. Some cooling vests have sleeves that cover the cooling packs and provide insulation. Layering clothing can help regulate the vest temperature to your comfort.
To use the vest: The vest usually has up to 6 Velcro closure pockets to house the cooling packs – 2 to 4 pockets on the front, and 3 to 4 pockets on the back. Place each cooling pack into one of the pockets on the vest. Put the vest on and close the front. Adjust the side straps to provide a snug but comfortable fit with the cold packs in place.
Source for Cooling Vest Information: http://www.va.gov/MS/articles/Keep_Cool_Multiple_Sclerosis_and_Heat_Tolerance.asp
You can contact the National MS Society at 1-800-344-4867 for a list of approved cooling product vendors or click on the this link for cooling products recommended by the MS Association of America.
http://www.mymsaa.org/msaa-help/cooling/
Other Good Resources
For more information on heat sensitivity and some recommended cooling products, click on this link: http://mymsaa.org/publications/motivator/summer-07/symptom-awareness/
Cooling Vests
The above strategies work well for most people, but this doesn’t mean that you will never have problems maintaining your body core temperature. When the “low-tech” methods (above) aren’t adequate, a cooling vest might meet your needs.
How does a cooling vest work? A cooling vest is designed to keep the body’s core temperature (around the heart and spinal cord) within safe levels to reduce symptoms of heat intolerance. The vest absorbs body heat, evaporates perspiration, and conducts cooler temperatures to the body through the skin. Cold packs for the neck, wrists and head conduct cold through to the arteries, cooling the blood circulating in the body.
When should I wear a cooling vest? The cooling vest should be worn in warm-to-hot conditions or when physical activity is planned. The vest can help keep you cool up to 3 hours when worn correctly, although this can depend on things such as environmental temperature, humidity, and your level of activity.
How do I use the cooling vest? It is beneficial to wear the cooling vest at least 30 minutes prior to physical activity. The cooling vest is more effective when worn over thin clothing and, when needed, when breathable fabrics are worn over the vest.
- Cooling packs: Initially, cooling packs should be put in the freezer overnight. Re-cooling them after use takes 30-60 minutes in the freezer. It does not harm the cooling packs to store them in the freezer.
You will need to experiment to determine which level of cooling you can tolerate and is most beneficial to you. Some cooling vests have sleeves that cover the cooling packs and provide insulation. Layering clothing can help regulate the vest temperature to your comfort.
To use the vest: The vest usually has up to 6 Velcro closure pockets to house the cooling packs – 2 to 4 pockets on the front, and 3 to 4 pockets on the back. Place each cooling pack into one of the pockets on the vest. Put the vest on and close the front. Adjust the side straps to provide a snug but comfortable fit with the cold packs in place.
Source for Cooling Vest Information: http://www.va.gov/MS/articles/Keep_Cool_Multiple_Sclerosis_and_Heat_Tolerance.asp
PLEASE NOTE: The medical information on this site is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. This information does not create any patient-physician relationship, and should not be used as a substitute for professional diagnosis and treatment. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition.
