Warm drinks and wear more layers or warmer clothes? Also, definitely keep your feet warm with socks+slippers+both, IBS tends to be triggered by cold feet and you’ll feel that pain in your gut.
It doesn't really matter what you do because it is that cold. Anything temperature that is 5oC or lower just cuts through what you wear.
Don't know why they don't just simplify things and publish them in one print book.
The worst happens to be with the YA books because most of them could have been published as a single standalone, given the length of them.