RonP I'm not using a heat lamp in my hen house I'm using a 250 watt bird bath heater 0r tank heater for the water that's all you mentioned there are better ways but did not elaborate ?
Sorry, I misread your post.
Heating lamps also come in 250 and 125 watt versions.
I didn't mention it because "cookie tin heaters" were already mentioned.
I have sucessfully used one for many years, and have not found a safer way to heat water while using electricity.
My concerns are with "anything" near or submerged in water, and any heating element accidently running out of water.
As are all mechanical devices, thermostats have been known to fail...