I have this condition known as fibromyalgia. To tell you the truth, it is quite common. Even though it is so common, the medical community doesn’t know all that much about exactly what happens to people who have fibro. The major symptom is chronic, uncontrolled pain. There are, however, many more symptoms. One such symptom is sensitivity to changes in temperature. In my case, excessive heat really makes my fibro flare up. I do not like to be without air conditioning. Since I live in the south, the heat is more common than the cold, but the doctor says that if I move up north, I might really need a good furnace as well as strong air conditioning. If I am outside for several days in a row, my fibro flare-ups will be terrible. In order to feel well again, I need to rest in a darkened room with lots of air conditioning. I have a friend who gets migraines, and she, too, relies quite a bit on the a/c to make her feel better. Also, my sister as multiple sclerosis, and she also needs her air conditioning to keep her feeling the best she can. My sister does live in a state where it gets both very hot and very cold, so sometimes she requires the furnace to help her through her MS flare-ups. It is funny that so many different conditions all demand good indoor air quality and strong a/c and heaters, right? I do not know what people used to do before air conditioning was common. I suppose people just suffered more.