If youve ever used an ice pack on sore muscles, imagine a whole body cooling machine that could treat everything from arthritis to wrinkles.Cryosaunas are making an appearance in Colorado, and some people swear by them.Roberto Mandje, an Olympic distance runner based in Boulder, trains regardless of the temperature."It's just about the mental fortitude," Mandje said. "You just have to get through it."He used to soak his sore muscles in ice-cold Boulder Creek, but he has now discovered an almost otherworldly way to put aches and pains on ice.Its called Cryotherapy.Candi Calkins with CryoTherapy Boulder said its the coolest spa treatment in Colorado.How cold is it?The air inside the chamber gets down to negative 200 degrees Fahrenheit, she said. So, its very cold.Heres how it works: You stand in the chamber while freezing cold air surrounds you, bringing your skin temperature as low as 30 degrees for three minutes.Cryotherapy providers claim that your body goes into survival mode, drawing blood to your core. When you get out, that nutrient-rich blood goes where it is needed most.Providers also promote a long list of potential perks, from better skin to weight loss."One of the unexpected benefits we've seen is increased libido, which has been kind of an awkward conversation to have with some clients," said Calkins with a laugh.Whole body cold therapy is hot right now with elite athletes claiming faster recovery, from the NBA to the Tour De France, to the cover of Januarys Running Times, Roberto Mandje."I've walked in very sore from training at the gym and then the very next day after doing a session I'm like, 'Oh my god! Where did the soreness go?'" said Mandje."Well, I've got to be honest with you. I'm skeptical," said Dr. Ted Parks, a sports medicine doctor at Presbyterian St. Lukes.Parks said surgical wounds can heal faster with localized cold treatments, but whole body cryotherapy hasnt been through rigorous scientific studies, yet."The experiment may work, in which case you get the benefit you're hoping for. The experiment may not, in which case you just lost a bunch of money," said Parks.Parks said it doesnt seem unsafe, but in one famous Cryotherapy crisis, an Olympic sprinter got frostbite on both feet because the socks he wore in the chamber were wet.Thats why Calkins at CryoTherapy Boulder provides socks and gloves.7NEWS Reporter Jaclyn Allen tried out the machine, and said it was refreshing, but she didnt feel anything profound."Certainly, you need to do more than one treatment. It's not like a tanning salon where you go in and walk out and have immediate results," said Calkins.After two months of Cryotherapy, though, Mandje is a believer.Its quite a rush, he said.Maybe, he said, its true -- what doesnt freeze you, makes you faster.Cryotherapy isnt cheap. Sessions run from $75 to $100, and are recommended up to three times per week.