In the 19th and early 20th centuries, the effects of heat on people with MS were used in the diagnosis of the condition. The hot bath test involved lying in a bath of warm water. If this caused or worsened neurological symptoms, it was taken as evidence that the person had multiple sclerosis.
This test has not been used for many years.
The hot bath test reflects the effect of heat that many people with MS notice. Hot weather, hot baths or showers, exercising or an infection can all raise your internal body temperature. The raised temperature can cause your MS symptoms to appear or worsen. This is known as Uhthoff's phenomenon.
