Iguanas are from the lizard family. These reptiles are cold blooded creatures that live in the deserts and tropics. If an iguana were warm blooded they would become too hot in the hot weather, but since they are cold blooded creatures they are able to keep themselves cool fairly easily.
These creatures are not very easy to care for and often die in captivity. If the proper temperatures are not reached within an iguana’s habitat this particular creature will be unable to digest its food properly and will most likely eventually die. After an iguana eats, temperatures of at least 85 degrees are required in order to properly digest food.
Each species has a preferred optimum temperature range (POTR) which refers to the temperature range in which these creature’s body organ systems work the most efficiently. Iguana’s usually have a POTR of 74 to 88 degrees Fahrenheit with a basking requirement of 88 degrees to 95 degrees Fahrenheit. If you have an iguana as a pet and it doesn’t seem to be acting normally than you should look for the following symptoms that may suggest brumation (winter) or aestivation (summer) hibernation: attempts to burrow away in the coolest place in the enclosure, lethargy, failure to adequately rouse when disturbed, anorexia, tonic rigidity, sleeping for long periods of time, and darkening of skin color.
If your iguana shows any of these symptoms you should talk to your exotic veterinarian immediately. Scheduling a physical examination for the pet to include bloodwork, radiographs and a fecal exam may also be necessary.