Plucky, WELCOME TO THE FORUM. However, don't spend too much time on the diseases subsection; you might catch paranoia--I'm not entirely kidding, either......
Thanks for posts folks.
Some seem to have misunderstood a bit. I am only planning to use an incandescent--non infrared--light bulb AT NIGHT ON COLD NIGHTS to keep the birds warm. I am not going to use one during the day.
Note: It was 38 degrees Fri. a.m. and I had a red light going all night. It might seem that a fully feathered standard sized chicken would be fine in that temp without assistance from heat. I was, let's say, 'intrigued' by the fact that all three birds in the coop had move on the roosts and were now on the part of the roost right near the light!
In other words, from this bit of eye-witness experience, AT LEAST SOME standard-breed sized, fully feathered chickens DO APPRECIATE A HEAT SOURCE EVEN WHEN THE TEMPERATURE DOESN'T SEEM THAT BAD. By am they were enjoying the head radiating from the bowl-like shield into which the red light was screwed.
Mine clearly appreciated it. I suspect yours will too.
Also, I believe I have seen the teflon coated bulbs, and if I have, you can tell. The bulbs I have--both real infrared heat lamps and the regular incandescent red light bulbs--are nothing but clear glass. IMO, if you can see right through the glass and it feels smooth, there is no coating.
Everybody LIGHT UP!!