The Walking with the Wounded team practised using cross trainers to simulate skiing for two hours at a time in the cold chamber.
More top news
The actress attended the annual dinner dressed in purple and sporting a temporary tattoo in tribute to pop star Prince who died last month.
Charity says there has been a big rise in employees unfairly treating pregnant women and new mothers.
Sadiq Khan has said that his prospects of being elected London mayor could be damaged by the party's poor handling of racism accusations.