Anita,
I don't have any suggestions on how to combat this problem, but Heather has experienced the same thing, both after RAD and now again after having chemo. We were told the RAD and chemo both can cause havoc with your body's temperature controls. It certainly is a pain in the neck, but I don't think there is much you can do except keep adjusting the thermostat or adding/removing blankets, turning AC/fans on/off, etc.
Rainbows & hugs,
Rosie