What light bulb for homemade incubator

[Mudambi Andrew]

I need advise on what size light bulb to put in my homemade incubator with fan. (size of a mini fridge) When I bought the incubator, I was told it ran off of 2 of the 150w lightbulbs. Well brought it home and it had readings of about 108 degrees. Ive tried different combinations of lightbulbs and can not get a number close to 100. What size light bulb or bulbs should I use? Thanks