People living with multiple sclerosis are subject to extreme heat sensitivity. When body temperature rises too high, MS symptoms are triggered to an exaggerated degree. Lying in the sun, taking a hot shower or sitting in a hot tub sound relaxing, but can result in a temporary flare up of symptoms. While there is usually no lasting nerve damage, it is still a painful and frightening experience. Awareness and taking care of oneself are the first steps in dealing with heat sensitivity.