AviTemp heat elements are completely dark so that normal sleep cycles are preserved. Higher wattage AviTemp elements can be used outdoors if protected against rain and snow.These are screw-in infrared elements that are a must for all bird lovers. With one of these elements and a ceramic-based reflector/lampholder, you can also create an instant hospital cage.Ceramic heat elements have no delicate filaments and will last up to 4 times longer than glass heat bulbs. Highly efficient, they produce even infrared radiant heat. Glass heat bulbs may waste up to 25% of their energy as light.