Kooky celebs are installing sub-zero chambers in their homes By Mara Siegler May 23, 2015 | 7:44pm Cryotherapy — the hot new health fad where people step into a 200- to 240-degree-below-zero F chamber for 1 ¹/₂ to three minutes — has become so big with celebs and bigwigs, some are buying their own machines. We hear that Relativity CEO Ryan Kavanaugh has his own cryotherapy chamber, as does Floyd Mayweather, who has been vocal about using the treatment. We’re told the high-tech devices run from $50,000 to $150,000. Mayweather pal Justin Bieber is also a fan and was spotted last week at Cryohealthcare in LA. Mandy Moore and Derek Hough have posted pics of themselves doing the treatment that’s said to alleviate everything from hangovers to chronic pain.