Dealing with cold

I wonder, in everyday life, when I feel really cold outside and I want to rush indoors for warmth, how these ascetics deal with it. I understand coldness is a part of reality and must ideally be experienced when it presents itself with a calm mind. I'm curious how ascetics, like the Buddha and his followers, manage this since they lived in the forests for extended periods without heating or modern amenities. How is it possible for them not to get sick or die from diseases and cold? More importantly, in the early stages of renunciation, how do they resist the urge to return to civilization? Sorry, if its a silly question, But I have wondered about it every day these months, without finding an answer yet. Thanks