I used a 60 watt ceramic bulb indoors for our amphibian tank. As I was cleaning the tank one day, I stupidly put the clamp lamp down on the table surface. Five minutes later, I smelled something burning. Yup. Those things get really hot. If you use a ceramic heat lamp, never rely only on the clamp attachment to keep it secured; always have a chain or something similarly secure to keep it where you put it.
You've got to consider the possibility that a chicken will fly up, into or on the lamp, so a cover over the bulb is needed, too. Chickens can burn themselves on the bulb, otherwise. It happened to someone we know here last winter. One of her hens burned her comb badly.
You also need to put a ceramic bulb in a fixture that has a special ceramic socket. A metal socket won't do. So if you bought your lamp fixture elsewhere (not at the pet store), make sure you've got the right kind of socket in the fixture...or else be prepared for trouble.