I talked to my doctor two years ago about intermittent fasting, and he had no clue what I was talking about, even though the winner of the Nobel Prize a few years back proved that fasting worked to change the body and also when your body attacks it own cells for energy, it goes after weak and radical cells first. So a three to ten day water fast 1-2 times a year is a really healthy thing to do. Today it is all the rage.
Anyhow, the President is controlling the discourse again and the media bit hard. He knows of studies. Hyperthermia is used to treat cancer. UV treatment of blood was being used up until the 1940s when antibiotics became common. There are also studies in which hydrogen peroxide, a disinfectant, is injected into the blood.
BTW, the Russians used UV and Hyperthermia much longer than we did in the West, as availability of antibiotics was limited due to the cold war.
Also, these therapies are thought to be a fallback for antibiotics once we are post Antibiotic age.