Prince Harry of Wales spent one night inside what is technically a giant freezer, a day after he turned 29.   His time inside the cold chamber is in preparation for his upcoming expedition to the South Pole, a part of the awareness campaign of "Walking with the Wounded" of which he is patron. 

Prince Harry takes down his tent after sleeping in -35C in a #ColdChamber exercise for #SouthPole2013 @supportthewalk pic.twitter.com/ZU1iHAPZis

— Clarence House (@ClarenceHouse) September 17, 2013

"Our expeditions are held to raise awareness, to show the public who our wounded are, to tell their stories, to highlight the support they need," says the Walking with the Wounded website.  "They are also to champion these extraordinary people who do not give up despite injury, who continue to face challenges with determination and courage." 

The 29-year old royal stayed inside the chamber for 20 hours with his team, and simulated what they will likely be facing when they embark on the "Walking with the Wounded South Pole Allied Challenge 2013."  Inside, they experienced ambient temperatures of minus 35C, which dropped to as low as minus 55C with wind-chill, and freezing winds that blew to as much as 45 mph. 

"He spent around 20 hours in the cold chamber at Mira in Nuneaton where cars and military vehicles are put through their paces," stated the Prince of Wales website. 

How hard can it be to put a tent up at -35°C with gloves on? #TeamGlenfiddich @VirginMoney #extramile #SouthPole2013 pic.twitter.com/Rnw1T2QDiW

— WWTW (@supportthewalk) September 16, 2013

His team also practiced putting up and taking down tents at minus 35C, while wearing thick gloves and protective clothing; as well as riding stationary bikes with environmental wind speeds of 60 mph. 

Cool pic of #TeamGlenfiddich on the exercise bikes at -35°C, the winds have been put up to 60mph #SouthPole2013 pic.twitter.com/ibXdPZ2a1J #WWTW

— WWTW (@supportthewalk) September 16, 2013

His Royal Highness will go to Antarctica together with Team Glenfiddich representing the UK, along with Team US and Team Commonwealth (Australia and Canada) this November.  They will later embark on a 16-day expedition, traverse 335 kilometers of harsh conditions at -35 degrees C, and aim to reach the South Pole by December 17. 

When asked what the worst part was about the simulation, he joked, "Going in."