Floyd Mayweather -- -220 Degree Cryotherapy Bath ... To Heal Body

Floyd Mayweather will do anything to beat Manny Pacquiao ... even subject himself to -220 degree nitrogen gas during Cryotherapy sessions ... intended to heal his body.

TMZ Sports spoke to David Levi ... owner of SubZero Recovery in Vegas ... who tells us Floyd makes daily ... and sometimes nightly ... trips to his business for the insanely cold therapy.

The Cryo sessions last 90 seconds to 3 minutes ... and according to Levi, it helps to enrich blood, expel toxins and also does a bunch of other cool stuff.

"Floyd comes in every day," Levi said, "I'm used to getting calls at 3 or 4AM with Floyd asking me to open the facility so he can use the machine."

As for the misery of sitting in -220 degree cold ... "Floyd hates getting in, but he knows what it does for him, so he tolerates it."