With these freezing cold temps I still want to work in the garage. My little electric heaters aren't keeping up.

Thinking of this style of heater:

Sunnydaze Decor, 40,000 BTU Forced Air Propane Heater Auto-Shutoff, Heat Type Other, Heat Output 40000 Btu/hour, Heating Capability 225 ft?, Model# BAO-118 | Northern Tool

Are propane heaters safe to use in a garage where I might be working on vehicles? I think ventilation is fine I'm more concerned about flammability.

Also my other hobby is collecting and restoring old Coleman lanterns, the kind that use liquid fuel. So I might have fuel exposed if I open up the tank (fount) on one of my lanterns. Obviously I'd have the heater far from any work space but I still worry about any kind of open flame when I'm working around gasoline.

What are you all using in your garage/workshop/barn?

Would kerosene be any better? My only gripe with kero is I hate the smell.