Cold Heat
Price: $20
If you’re looking for a good holiday gift for a tinkerer you can hardly give away anything more inventive than the Cold Heat soldering iron. It redesigns something that’s been virtually unchanged for decades. The idea is this: instead of running electric current through the tip of the iron to heat it up, the Cold Heat iron runs the current between the two prongs of its split tip, and thus through the solder. If you make a good connection, the solder is effectively electrocuted and melts in a second. When the iron’s split tip is removed from the solder, it cools down quickly, becoming safe to touch in a few seconds. And unlike a regular soldering iron, the Cold Heat contains it’s own power source, four AA batteries. No need to plug into a wall outlet.