Heat sensitivity in patients with MS

I wanted to just touch on the subject of heat sensitivity in multiple sclerosis patients. MS patients are more sensitive to heat/ temperature as compared to non MS patients. It has been seen they do “poorly” whenever their body temperature is elevated. So when MS patients have fever, they become weaker and their neurological deficits become more prominent e.g. more blurring of vision, diplopia, ataxia and cerebellar dysfunction. Thus infections such as pneumonia and urinary tract infections (UTI) warrant to be aggressively treated with anti-pyretics and antibiotics.

Why does this occur? Well the thinking is that as the temperature of the body increases, it promotes cross-talk among the demyelinated axons and also leads to conduction blocks (block in the conduction of impulses in the neurons). This exacerbates preexisting neurological deficits.

So it follows that MS patients do better in colder environments as compared to warmer places.  Better in winter as compared to the heat of summer. Keeping the ambient temperature of your house a few degrees below “normal” may be worthwhile though there is no scientific data to back this claim.


Nitin Sethi, MD