Personal Warm+Cool System

The neck-worn Personal Warm+Cool System produces both heating and cooling for one’s body. The system uses electro-thermal principles to create winter warmth and summer cooling by reversing the flow of an electrical current. The device weighs only 8 ounces and can operate for up to 10 hours on power from three C-size batteries.

Cost: $70 (No longer produced at source, but found at various suppliers)