Monitoring temperatures is a vital part of Iguana care.
I recently bought a no-contact Temp Gun and now I know why everyone says how great they are!
Aside from getting a direct temperature reading from your Iguana or snake or other reptiles, they are great for measuring surface temps of most things like hot water, baths, food, feeders, kids, just about anything you can aim it at!
I paid $35.00 for mine which was caught on sale (a $49.00 retail value at Radio Shack).
This site has a model for $25.00. If you can swing it, it's well worth the money for such a handy little gadget.