If winter is harder than summer (except for the high temperature problem) for others, are there any studies to suggest why? Is it relative humidity, the cold, barometric pressure, or . . .? Even in the house with the air "conditioned", it seems that I struggle all winter, and then struggle in the spring to regain the muscle tone that I lost during the winter due to poor lung function which caused me to exercise much less than I need to in order to maintain the basic muscle tone needed to get the summer chores done. I've tried to condition the air with regard to the temperature and humidity, but it doesn't help me to keep exercising through the winter the way I need to. Sorry it is so long winded. GlennD