The theory behind the treatment is that in extreme cold the body tries to protect vital organs by with-drawing blood from the limbs, taking lactic acid and muscle damage with it.
The science suggests the body recovers quicker from training, which means more training can be done, with players becoming fitter.
Wales are said to be the only international rugby team to use cryotherapy as a training tool
Coach Rob Howley, Warren Gatland's assistant at Wales, told the Daily Mail of the gruelling training and cryotherapy sessions: "As a coach, you need to see players under these conditions before you select them. You'd rather find out before a test, so we manufacture those conditions here. This facility is unique. It allows us to put those players under pressure, not only from a physical perspective but mentally as well."
The bad news for the Welsh players is that all the hardship counted for little in their disappointing performances against Argentina and Samoa. Against the Samoans they were submissive and appeared to lack stomach for the fight against a team well-known for its hard-nosed approach. The other bad news is that they will have a cryotherapy chamber built at their training base outside Cardiff in time for next year's Six Nations. The project will run into hundreds of thousands of dollars; their own torture chamber won't come cheap.
Wales aren't the only team to go down the scientific route in a bid to eke out marginal improvements.
England coach Stuart Lancaster has signed sports scientist Matt Parker, who helped British cycling to success in Beijing and London, to the management team.
Parker was involved in paving the way for Bradley Wiggins' Tour de France triumph this year - he worked with the former track cyclist ahead of his unexpected fourth place finish in the 2009 race, changing his body as well as his mindset.
Parker is said to be an expert in seeking out marginal gains, telling the media during the London Olympics: "We are obsessed with getting the details right; we are relentless in pursuit of it. It's not easy for other federations to do, because of the details involved. It's about everyone being the best they can be - the carer not leaving anything behind, the mechanic testing everything - but it's not just two weeks. It's two months, two years. When you put that in place, your chances of success are higher."
Of course, rugby players could just go out and run a bit. After all, the countless hours All Blacks captain Richie McCaw puts into that old-fashioned approach appears to have worked well for him. His side is regarded as one of the fittest in world rugby and, while Steve Hansen and co are always on the hunt for advantages, there is no substitute for hard work.
