Garage Heating

As I don't have a garage now. When I did, I used a kerosene heater and it would take about 1/2 to 1 hour to heat it up. I also kept a window open about 4 inches during the heating.
I worked construction years ago and had to stay inside a building to keep the kerosene heaters filled to help dry the concrete. I made it thru the night but missed 3 days work afterward due to poisoning from the kerosene burning. NEVER run a kerosene heater without a good vent.