How cold does the ice bath have to be?

When starting a new ice bath practice, most people will feel the cold shock response at cold water temperatures less than 60F. But as they become acclimated by building brown fat, temperatures that used to feel cold will instead feel comfortable.

In this excerpt from my conversation with Mike Mutzel (High Intensity Health), I explain that anything more than 39F doesn't feel cold enough to me anymore.

I want ice in my ice bath.

A good rule of thumb is "Go cold enough to gasp, long enough to shiver."

If you don't feel that gasp reflex, the water isn't cold enough to stress your central nervous system and build your psychological resilience