If already experiencing a bacterial or viral infection, cyclic hyperventilation breathing or deliberate cold exposure may be detrimental.

“if you are feeling malaise, if you're feeling like you have to rest you're tired, you're not feeling good because of a cold or because of a flu or because of a bacterial infection, now, I'm not saying just feeling not good, I'm saying feeling not good due to a cold or other form of virus or bacterial infection, then I would say stay out of deliberate, cold exposure. Don't use it.”

“But if you're already coming down with a bacterial or viral infection, why cyclic hyperventilation breathing or why deliberate cold exposure may actually be the worst thing if you are already contracting or have contracted, if you are contracting or have already contracted a cold or virus.”