Keeping Cool in the Summer Swelter

Patient Expert

Hot " hot " hot!!

The summer brings with it the 4th of July, hot dogs, fireworks " and sweltering heat. People who have MS know all too well that summer can be a difficult time because of the heat and its effects on the symptoms of MS.

So what is going on and is there anything to do about it?

Just like you can take someone without MS and heat them up enough to cause heat stroke, there is a temperature threshold where nerves in people with MS work best - and this threshold is lower than in people with MS. This means that while your loved one might be enjoying the sunny rays, you might be regretting forgetting the sun umbrella and see them as pseudo-exacerbation rays.

Pseudo-exacerbations are just that "pseudo," which means that they look like exacerbations but are not. MS relapses (exacerbations) are usually characterized by new neurological symptoms lasting for longer than 24 hours (but usually more like weeks to months). Examples include optic neuritis (blurry vision), transverse myelitis (band-like feeling around your trunk and weakness), weakness on one side of the body, double vision, and so forth. MS exacerbations (relapses) are usually new to each individual MS patient (making MS unpredictable), but pseudo-exacerbations are an uncovering of older exacerbations. This means that when it is hot outside you may feel a returning of older neurological problems you have had in the past. For example, your vision might be blurry in the same eye where you had optic neuritis in the past. This is called Uhtoff's Phenomenon.

There are other ways of getting hot besides the external heat of the sun - there are internal and external causes of heat. Internal causes can be fevers, menstrual periods, exercise, and even stress. External causes can be the temperature outside and not drinking enough fluids.

Some people with MS, however, do not seem to be affected by the heat and others have the opposite effect with cold - they feel better in the heat and can't tolerate the cold. But most people with MS need to find strategies to keeping it cool.

The first strategy in staying cool is to recognize that it is important and to make adjustments in your plans based on this - this does not mean staying away from the beach, but it does mean to plan wisely. If prolonged heat exposure makes you feel fatigued, have blurry vision or weak, then it is probably not the best idea for you. The good news is that as far as we know it is not actually dangerous usually, but if you don't feel good, then that itself can ruin your summer plans. You should be sensible in the heat and know your own body and when it is time to get out of the sun - and like everyone else, always protect yourself from dangerous UV rays.

Escaping into an air-conditioned space may not be enough though, since humidity is one of the biggest culprits in the problems with heat. This means that you should stay very well hydrated and keep drinking that nice cold water.

Some people like to put cold towels or cooling scarves around their necks or wear cooling wrist bands; others choose to use cooling vests. Cooling vest can be active or passive - meaning that these vest can keep you cool by actively acting as individualized air-conditioning units (most people do not use these, often bulkier, NASA technology vests) or there are vests which have little beads in them and you dip the entire vest in water and it cools you as the water evaporates or there are vests where you put ice packs in them to keep you nice and cold. In places with high humidity (like Florida), you want to stay away from the evaporative vests because they won't work so well.

Luckily, both the MS Association of America (MSAA) and the MS Foundation (MSF) have programs where you can apply and receive free cooling devices, including vests. Details about these programs appear in their quarterly magazines, the MS Motivator and MS Focus.

If you would like advice from people with MS living in Florida, please email