The 29-year-old, who will race with a team of injured British servicemen and women against United States and Commonwealth groups in November, was subjected to ambient temperatures of minus 35C, with wind speeds of 45mph.
Harry, patron of the Walking With The Wounded charity, joked that it was a cold night's sleep.
When asked what was the worst part, he said: "Going in."
He spent around 20 hours in the cold chamber at Mira in Nuneaton, Warwickshire, where cars and military vehicles are put through their paces. Click link for full post from The Telegraph.