Heat Intolerance and MS

While There Are No Treatments for This Symptom, These Tips Can Help

Young woman sitting at desk with fan
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Overheating can cause the symptoms of multiple sclerosis (MS) to flare in many people, a condition called MS-related heat intolerance. In fact, even a slight rise in core body temperature—we're talking one-half of a degree—can worsen symptoms, according to the National Multiple Sclerosis Society. This is because demyelinated nerves, which are already impaired with MS, have more trouble conducting electrical impulses in warmer temperatures. 

For this reason, you may feel considerably worse during activities that would otherwise be enjoyable for you, such as exercising or taking a hot bath. Sunbathing, being in very hot or humid climates, or running a fever can also be triggers for a flare-up. 

The good news is that heat generally does not cause any permanent damage or accelerate the demyelination process in MS. But it sure feels uncomfortable and can be painful. When your body temperature comes down, your symptoms will subside. To that end, here are some tips to cool you down. 


Cool Your Home Affordably

In the summer months, air conditioners are non-negotiable for those of us with MS. The cost of your home ACs may be tax-deductible if your doctor deems them medically necessary. Ask an accountant or CPA about the paperwork required for this. You can also lower your electricity bill by installing window tinting, which can cut your bills considerably in the summer months (and gives your house a nice “cool” feeling inside). This usually pays for itself within two years.

Use Personal Cooling Products 

There are a large variety of personal cooling products available, including different types of vests, neck bands, and hats. The Multiple Sclerosis Association of America has a ​Cooling Distribution Program to get these products to people with MS that need them but cannot afford them. Better yet, try making your own.

Eat Cooling Foods

In the summer especially, many people report that they lose their enthusiasm for eating, preferring an ice cream cone or popsicle to a real meal. While that is fine for an occasional treat, it’s important to get adequate nutrition so that you don’t worsen your fatigue with blood sugar fluctuations. 

Some ideas for healthy cooling foods include:

  • Raw salads with a variety of vegetables and fruit
  • Protein such as nuts, beans, eggs, fish or meat
  • Vegetables with healthy dips, such as hummus
  • Cold sandwiches
  • Gazpacho (cold soup)
  • Cereal topped with fruit and nuts and cold milk (or soy milk). 

Keep Chilled Drinks On Hand 

Drinking cold beverages can really help lower your body temperature. Keep a couple of plastic bottles filled with water in your freezer to take along in the car to drink as they melt (try this with iced tea or diluted lemonade). If you have the habit of starting your day with a hot cup of coffee, try iced coffee in the morning instead. Brew a pot the night before to keep in the refrigerator.​

Pre-Chill Your Body Before Heat-Inducing Activities 

Cool down before heat-building activities with a cold shower. Getting chilly before heading outside on a hot day seems to buy a lot of time before you feel the heat. You will have to experiment with how cool of a shower you can endure and how much it helps you, but you might be surprised at your increase in heat tolerance.

Take a Dip

Pools with water that is 85 degrees or cooler are ideal places for exercising or just relaxing. Head to a local public pool in the summer or a YMCA for their indoor pool any time of year. 

Watch Heat from Appliances

Many people have the habit of interfering with the jobs that their appliances are trying to do—opening a dishwasher mid-cyle to insert a glass or poking at food in the oven to "make sure it is cooking." The problem with this habit is that a sustained blast of hot air can be just enough heat to trigger your MS symptoms. If you can stand it, it’s probably better to let the machines do their jobs without your interference. It goes without saying that tasks required for cooking, like standing over the stove to stir a stew or grilling burgers outside, also carry this warning.

Install Misting Fans

Misting fans blow a fine mist of water into the air and can lower temperatures in the immediate area by 20 to 30 degrees. You've probably seen them at restaurants with outdoor seating or even amusement parks. They are a costly but really effective, solution to help you enjoy being outdoors in the summer months on your patio, deck or porch. They can be mounted to a wall or overhead beams, and there are also free-standing ones that sit on the ground.

Cool-Off has a website that explains the systems well. We installed our misting fans ourselves on our patio. I have literally had to put on a sweater when sitting under the fans in 85-degree weather.

Apply for a Disabled Parking Permit 

If you do not have a mobility assistive device, it may not have occurred to you to get a disabled parking permit. It not only makes parking easier, it also helps you avoid walking across blazing hot parking lots in the summer. This way, you not only conserve your energy by walking a shorter distance, but you minimize the risk of aggravating symptoms from the heat.

Some of you might have a list of reasons why you don't need a handicapped tag or be resistant to getting one for fear of what others might think. But if you are sensitive to heat, a handicapped tag can be a lifesaver during the hot months.

Get Out of Town 

Clearly, relocating to a cooler climate is the most extreme suggestion on the list and probably the least feasible (or desirable). However, if you are one of the unlucky people who start to “feel the heat” in mid-spring and don't get relief until mid-fall, it may be a quality of life issue that can’t be ignored.

If possible, at least take vacations to cooler places during the summer months. One affordable option is “house swapping,” where you trade houses with someone for a period of time (anywhere from a week to the entire summer). There are plenty of websites offering this service. The Independent Living Institute has an amazing accessible home exchange service that lets people in wheelchairs swap fully-equipped homes, many in exotic (and cool) locales like Iceland and Finland.

A Word From Verywell

While heat is a foe when it comes to your MS symptoms, try to not get discouraged. With proper planning and strategies, you can still enjoy the sunshine of summertime. Moreover, be reassured that your MS is not worsening when your symptoms flare up with the heat. They will subside once you cool off.

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Article Sources

  • Davis SL, Wilson TE, White AT, Frohman EM. Thermoregulation in Multiple Sclerosis. J Appl Physiol (1985). 2010 Nov;109(5):1531-37.

  • National MS Society. (n.d.). COOL IT! Beat the Heat. https://www.nationalmssociety.org/Chapters/COC/Services-and-Support/Services/COOL-IT.

  • National Multiple Sclerosis Society (n.d.). Heat and Temperature Sensitivity. https://www.nationalmssociety.org/Living-Well-With-MS/Diet-Exercise-Healthy-Behaviors/Heat-Temperature-Sensitivity.