by Amit Kohli, MD
August 14, 2026
It’s the height of summer, a time that for many can mean escaping to the outdoors, vacations at the beach, and hours at a time in the sun. For many people with multiple sclerosis, however, this can be a tough time of the year to push through. In this article, we’ll discuss why that can be the case and some strategies to keep some of these effects at bay!
How can heat cause problems for people with Multiple Sclerosis?
Multiple Sclerosis is a demyelinating condition, which means that primarily what is affected is the myelin sheath—the insulating layer around a nerve. This means that for many people with Multiple Sclerosis, signals are still able to get through some areas of injury, but oftentimes will have a harder time and require more energy while doing so. As a result, factors that make your nervous system run less efficiently can sometimes lead to blocks in conduction that people may experience as temporary fluctuations in their old symptoms, or increased fatigue as your nervous system uses more energy to function (though if you are having symptoms, you should always speak with your doctor to confirm!) . At the top of the list of possible exacerbating factors is, of course, heat! This can come from hot showers, saunas, heating up during exercise, or a hot day.
What are some strategies to help manage the heat?
For those times when you can’t stick to the air conditioning, there are a few things you can do to help.
- Water – Hydrating well with ice water (not just cold water from the tap!) has been shown to increase function and help with fatigue in people with multiple sclerosis. Keeping a thermos of ice water with you throughout the day, but especially when outdoors on a hot day, can offer a convenient and effective measure to ameliorate the effects of heat.
- Cooling Garments – Cooling vests, necklaces, and bracelets are an important second line treatment which have shown excellent efficacy in helping manage heat during exercise. These can be purchased in different forms, though some cooling vests can come with the drawback of being a bit clunky.
- Precooling and frequent breaks when exercising – Taking a cool shower prior to exercise and taking frequent breaks can build resilience to heat buildup! For this reason, short bursts of exercise as is done in strength training rather than endurance training, can often be easier to tolerate.
- Swimming in unheated pools – The gold standard for exercise and staying cool on a hot day, though this is not always an option for everyone and not every day. Swimming in cool water offers mechanism for constant heat regulation and can be a great strategy to keep heat related symptoms under control.