I got the Coleman Black Cat catalytic heater.

I used it twice in a tent, being careful and all that. It generates a very decent amount of heat, but depending on tent design, it may or may not warm the tent up that much.

I bought it after a camping trip where my girlfriend was very, very cold during the night. Since she won't invest in good gear, I had to buy the Black Cat for the "psychological effect". She finds it's helpful, so hey, good buy.

I guess such a buy is an investment. You don't use it very often, but once in a while, it comes in handy. It's also useful for emergencies in the winter.

In regards to camping though, don't count on the thing to make the tent very warm. If your girlfriend wants to get good gear, I would go that route instead.

Bye!