Although hot water is therapeutic, it can increase your temperature sensitivity and lead to homeostasis. If FMS and ME/CFS patients are heated like this, it will require a lot of work for them to cool off and go back to their normal temperature. Some of them will end up getting overheated which causes them to sweat profusely after showering. Sometimes, the temperature sensitivity can also trigger other symptoms to flare up. Therefore, it is important to be very careful with water temperature when showering.
Fibromyalgia patients suffer from painful condition known as tactile allodynia. With tactile allodynia, a patient can feel pain even from a non-harmful touch sensation. For instance, the brushing of fabric on the skin or a gentle tap on the patient are sufficient to cause pain to the patient. Showering can be extremely painful for fibromyalgia patients with tactile allodynia. The pain is caused by the contact of water droplets falling onto their skin.