I noticed that temperature has rarely any noticeable effect on the characters wellbeing. Only in very extreme regions it forces you to invest a bit into protection.
I would love to see a more dynamic system. Let temperature vary over times of the day. For example let it be super hot around Noon in the desert, so that you would not want to go out. Or let the night bring grim frost in the northern areas. You could also use weather to alter the temperature and being wet could have a greater impact. Give it a thought please.