This is why, for a book that takes place a few years from now where there's a global power outage and a huge volcanic eruption has caused a second 'year without a summer', the characters mention how cold the insides of their nostrils are. One guy lives in a room that's far from the only fireplace so he reveals how he tries to stay warm so he can go to sleep. It involves exercise and hot tea and he confides it all goes to pot if he has to whiz during the night.
So many new authors in particular really skip/skim over this and it does them no favors.
I think this is also a reason why fan fiction appeals to a lot of newer writers: these decisions have already been made.