 Preliminary and proof-of-principle studies of Hof's method, as well as similar breathing practices, have shown that hyperventilating can temporarily suppress the innate immune response as well as temporarily increase heart rate and adrenaline levels.However, the broader medical claims made by Hof, such as the treatment of cancer and auto immune disease, have not been validated by any rigorous peer reviewed research.When exposed to cold, the human body can increase heat production by shivering, or non-shivering process known as thermogenesis in which BAT, also known as brown fat, converts chemical energy to heat.