If it is the old catalytic style of Coleman heater, you fill it up then turn it over until you get a wet spot on the screen. Then you light that and capillary attraction takes over.
Don't use them in an closed space, like a sealed up tent. They use up all the air and "will" kill you. Always leave a window open a little so there is an exchange of air.
Hi all, Metalbasher is absolutely correct about the carbon monoxide killing you in an enclosed, unvented space. A cousin of mine died many years ago this way. He had just started a job as a security guard and it was his first night on the job. Fired one of these up in a car. Very sad. This typ of heater is best used where there is good ventilation.
When you are cold you may turn to desperate measures, psychologically, a cold house or environment to most people is ver unsettling. I knew another guy that was unemployed with a wife and child. Fired up his CHARCOAL barbecue IN the house. They survivied.
Good idea to always have blankets, and heavier clothing to layer for a worst case scenario. Not comfortable, but uses no fuel, and is affordable, and is almost always available.
Rubbing alcohol should not be used to start a catalytic heater, it, it is usually about 50% water.
I have the old green Coleman catalytic heater, a 5K BTU model, I believe. Used to belong to my uncle. It's quite handy, and should be used with Coleman fuel (also used to start it). I suspect it could be used with unleaded gasoline, i.e., I don't believe there'd be anything in it that would poison the catalyst, as the lead in the old-style gas would have. However, I've never used mine with anything except Coleman fuel. You fill the tank with the heater COLD, then you pour a few ounces of fuel on the dome and light it. That gets things going pretty quickly, and in 10 minutes or so you should have a nice glow in the dark from the dome and good heat. As has been mentioned, you never, EVER use any type of heater indoors that employs regular combustion, i.e, which uses oxygen. It will use up all the available oxygen, but the CO (carbon monoxide), produced by incomplete combustion as the oxygen supply dwindles, will probably kill you before you suffocate.