You just have to be quick with it. 'Cold Heat' is a dumb name, it makes lots of heat, you just need to make an electrical connection between the two halves of the tip, then it heats them up with current so you can solder the joint. When you remove it, the circuit is broken and the current stops, and the tiny tips cool down very quickly because of their small size. Try sticking the tip against your tounge if you want to experience how hot it really gets.
(note, don't actually try that).
I don't think they are too hot for small electronics.. I normally use a 35W with a tiny tip and just work fast. I'd actually like to get one of these doodads for my general electronics work around the house, keeping my other irons for precision work at the bench. Just remember that 'cold heat' is still heat, and if you are working on sensitive items with short traces and leads you'll still need clip-on heat sinks.
Neat item though.
peace,
sam