Ian was still feeling cold, but he had wrapped himself in an electric blanket, and was feeling much better after drinking soup and hot water. He had gotten an update on Mina who was still asleep, and still shivering and he was told that women were more susceptible to cold due to several biological factors, but mostly because of the fact that their core temperature was higher than a man's.
Mina had also spent more time in the cold that Ian did. He was warm in his car while she was walking in the cold. He really hated his behavior, but it was the kind of outburst that he had been having increasingly regularly and something that Zane mocked him about.
Ian was sexually frustrated and unimportant things were setting him off in ways they had not before. When he had no sexual experience, it was easier for him to ignore his urges, but now they were causing what he could only describe as mood swings.