Sit on a 50 watt heating pad.

Sit on a 50 watt heating pad. Rather than heating the whole house or room, sit on a low wattage heating pad. You can also make your own heating pads:

• Use a hot water bottle. It's great for warming your hands and lap while sitting; also put it under the covers at the foot of the bed.
• Microwave socks or small homemade "pillows" (also known as heat packs) filled with rice, dried corn, or beans for one minute in the microwave and use as a heating pad or bed-warmer.