Like someone else stated they have different colored flood light bulbs that are very inexpensive and come in 100 watts. I have bought the red ones before and they work great! For my poorly insulated outdoor coop last year when it was -40 for a long time I used a 250 watt heat lamp on 24/7, during the day the pop door was open to the draft free run so it didn't really keep it too warm, at night it kept it above freezing when the pop door was closed.