Why do people with ms prefer to do exercises in a cooler climate?

Sensitivity: Hot surroundings make ms symptoms transiently worse, and since fatigue is also present, best to exercise with cooler surroundings. Interestingly, more ms is found in northern climes, i.e., north of latitude 39 or 42. Of historical interest, hot bath test was once used to make diagnosis. Heat problems are reversible when cooler areas are sought.