You can rent them online, although the price is a bit more...
Thermal Camera Rental
Another option is to purchase an infrared "laser" thermometer. Although not quite as simple to operate as a flir camera, they provide the same information. And you can't beat the price: many are under $50. Once you buy one, you will love it!
My favorites, in order, are:
Black & Decker TLD100
Kintrex IRT0421
Mastercool MSC52224A