For two winters now, I've been using the simple cookie tin heater that I made, using an ordinary coffee mug warmer inside it. It took about ten minutes to make and
works wonderfully well.
Take the cookie tin and pierce the side of it with an awl or something and then enlarge the hole until it's big enough to accept the plug from the mug warmer.
Use a smidgeon of any sort of tape over the sharp edges of the hole that you've made, so the sharp edge can't dig into the wire.
Put the mug warmer inside the cookie tin, and thread the warmer's plug through the tin's hole from the inside of the tin. Pull the wire so there's no excess still
inside the tin.
Put the cover on the cookie tin.
Using tape again, cover the hole where the wire is coming out of the tin.
The mug warmer looks like this:
You can buy them for under $10 at amazon and other online sites.
Then I just dug a hole in the ground inside the chicken's run. Just deep enough to take the cookie tin, so that the top of the tin's cover is level with the surrounding earth.
Then I took the plug and lifted it straight up into the air until it met the end of the extension cord that I have hanging down from the wire mesh ceiling of the run.
Then I set the enameled water bowl (I use an old enamel bundt pan) right on top of the cookie tin.
All done.
works wonderfully well.
Take the cookie tin and pierce the side of it with an awl or something and then enlarge the hole until it's big enough to accept the plug from the mug warmer.
Use a smidgeon of any sort of tape over the sharp edges of the hole that you've made, so the sharp edge can't dig into the wire.
Put the mug warmer inside the cookie tin, and thread the warmer's plug through the tin's hole from the inside of the tin. Pull the wire so there's no excess still
inside the tin.
Put the cover on the cookie tin.
Using tape again, cover the hole where the wire is coming out of the tin.
The mug warmer looks like this:

You can buy them for under $10 at amazon and other online sites.
Then I just dug a hole in the ground inside the chicken's run. Just deep enough to take the cookie tin, so that the top of the tin's cover is level with the surrounding earth.
Then I took the plug and lifted it straight up into the air until it met the end of the extension cord that I have hanging down from the wire mesh ceiling of the run.
Then I set the enameled water bowl (I use an old enamel bundt pan) right on top of the cookie tin.

All done.