No, I think a 60w would be fine. Just a little heat. I wonder if the inverter could be connected directly to a spare car battery to run a 60w bulb. I have a Honda so when it's off it's off so anything plugged up will not work.Ok do not try to run a 250w heat lamp on an inverter from a car or truck. In looking into it this morning most cars wiring will not handle the load. You will blow a fuse or if u have to large of a fuse in your plugs circuit u can burn up wiring.one 125w heat lamp is going to be pushing the limits on most cars wiring. It is not the size of the inverter that is the problem it is the wiring from the plug in the car to the battery that can not handle the load. Just a heads up for everybody.