Best way to heat an outdoor enclosure?

[beachylivin]

I built my leopard tortoise a large wooden box, caulked it and put a sealant on it. I am trying to decipher what heating method to go with, but I am leaning toward a heat pad. Whether I go with a ceramic lamp or a heat pad, I still need to somehow keep the cords inside the box and run an outdoor extension cord into the box. If I do go with a heat pad, what brand does everyone recommend? Kane, K&H, Osbourne, etc? What wattage is recommended. How do I ensure my tortoise won't burn itself? Any suggestions would be appreciated, thank you!

 

[LeaderLeprechaun]

could you post a picture of the enclosure so i can see what your working with and the possibilities