Infra-red saunas put out wavelengths that extremely bio-compatible, indeed, some of them actually match the wavelengths the body itself emanates. In practical terms, these wavelength penetrate into the body, if I remember correctly, about one-and-a-half inches or more. This is different and distinct from a hot-coil sauna that predominantly raises the temperature of the air at the skin’s surface. The ambient temperature in an infra-red sauna may not get much above about 120 degrees F. Mine gets to about 130-ish after it’s been on for about an hour. Generally, very pleasant and the air is NOT scorched or hard to breathe. And the infra-red sauna experience feels very easy on the heart.
The penetration of the infra-red has a number of benefits, including muscular ache-and-pain relief, but additionally, it excites a different quality of perspiration. Not only more liberal, but also of a different quality. The perspiration due to infra-red contains higher quantities of fat and solids. Solids such as toxic metals, like mercury, for example.
This is just me talking for a minute, but I estimated that about seven half-hour saunas equated to the loss of about ONE POUND of those fats and solids. Understand, that’s not water-loss I’m talking about, which would be more like an additional six pounds (making seven total). Of course, the water loss will be, and in fact NEED to be, replenished, but those fats/solids are out there, man!
Looking at it another way. Every “so many saunas” could be taken to be the equivalent of an EXTRA bowel movement.
Anyway, in passing, as I’ve mentioned in the past, infra-red technology saunas are a modern equivalent of “sweat lodges” using hot stones. Indeed, some saunas use ceramic heaters, very much equivalent (to my mind anyway) of hot stones.
And, after experiencing infra-red, I don’t think I could be persuaded to even go into a hot-coil sauna anymore. When I look back, those hot-coil saunas almost seem traumatic in comparison to the gentle but powerful infra-red ones.