Thanks mickeg, more interesting stuff. By the looks of it there's no heat sink, that can't be right can it? In a plastic case there must be some way to dissipate the heat.
I accidentally left my 200 lumen metal cased battery light switched on for half an hour when I wasn't moving, I couldn't touch it for a good while it was so hot, I don't think we realise how hot these things get when the air isn't passing over them.