I think it's legitimately beneficial as well to raise core temperature when suffering from an infection. In fact, for fever vaccine therapy, we recommend pre-warming the patient so that rigors are not as severe. And saunas in general are likely quite healthy, partly due to the production of heat shock proteins.

For cancer therapy, I don't think that type of hyperthermia is as effective as fever therapy and I suspect that will turn out to be the case for the treatment of occult infections and autoimmune disease as well.