Re: HEAT...short term relief..long term pain???
IME, part of the longer-term issue with pools, jacuzzis & hot tubs is related to the sanitizing chemicals (chlorine & bromine) added to the water. The fluoride in water in most communities also enters the body through the skin, esp. when the water is warm or hot. The chemicals chlorine, bromine, and fluoride bind to iodine receptors throughout the body, and can cause thyroid hormone resistance at the cellular level. People vary in how adept their bodies are at getting rid of such toxins, but research is showing pretty clearly that at least one subgroup of fibro sufferers has significant deficits of the enzymes that deal with such toxins.
Saunas, esp. infrared saunas, have been known to flare up collagen vascular diseases like lupus. FIR (far infra red) has been known to fire up certain cytokines that promote inflam, in those who are genetically predisposed ...
The FIR saunas I've explored have been shown to mobilize toxins like heavy metals, mercury. If one is able to sweat them out directly, great. But if the toxins are mobilized & incompletely excreted, a flare may result. Most people undergoing serious chelation/metal detox are quite familiar with the sick, flu-y feelings associated with the process. Again, if one is in the subgroup of fibro sufferers with poor enzyme & glutathione function, mobilized metals will be a problem.
There's a relationship between metals in our bodies & viruses, but I'm not familiar with research about how a sauna experience with metal detox relates to viral loads. Many people with fibro & CFS have chronic, undocumented viral infections contributing to their pain & fatigue.
Most experts on FIR sauna recommend building time & temp up slowly ... start at 120 degrees for about 10 min. Do not increase time & temp until reactions are held to a minimum.
I have a neighbor who is a retired physical therapist. He told me that although heat is soothing in the short term, it is nowhere near as effective at pain reduction as ice. The cold reduces and in some cases, halts the firing of pain-nerve impulses. The downside of cold is that much of the muscle pain of fibro is due to hypoperfusion of muscle tissue. Warmth aids circulation to the tissue, while ice/cold increases hypoperfusion effects.
So my conclusion is that both heat & cold have their pros & cons for fibromites. I have a ceramic bead infrared heating pad that I fire up in my microwave & use on occasion (haven't for quite a while due to progress). I've tried a FIR sauna but like you had major regrets, mine for about 2 weeks post-sauna. I understand the principle behind the ice, but rarely use it as the short-term relief isn't worth the longer-term muscle aching, IME.