You're dehydrated. Drink more water, and keep your windows open during the day. Close your curtains at sunset and you should stop bugs flying in (they're going for your lamp or shiny computer screen). A fan won't actually cool you down but it might help circulate the air more, preventing it from getting too hot.
The older your computer, the hotter it tends to be. If you happen to be a techie, or you know someone who is, see about replacing the cooling fan with something a bit more effective. It can help PC performance as well as your room temperature.
Water is definitely the most important thing though. Make sure you drink plenty, and while it's still cold.