An iguana's natural habitat is the rain forest, and to keep yours healthy and happy you should try to recreate these conditions. Start with a large aquarium, at least 50 gallons. An iguana will quickly outgrow anything smaller. Temperature is all-important. Keep your tank no cooler than 75 degrees at night for young iguanas or 65 degrees for adults. Avoid products known as hot rocks. They can actually be dangerous. Instead, use shielded light bulbs to heat the enclosure--a white one during the day and a red or blue one at night. Try to give your iguana a few minutes of direct sunlight each day. Natural light helps the animal synthesize vitamins. Humidity is the other major factor in creating a climate. Iguanas like it far more humid than humans do. Misting your pet occasionally helps, as does adding a wading pool. Be sure to change the water daily. Water is a favorite place for lizards to eliminate waste. With a new iguana, let it gradually get used to being handled. Limit yourself to petting the animal for the first few days. Don't be alarmed if your iguana sneezes. Humans remove excess salts from their bodies by sweating. Since iguanas don't have sweat glands, they sneeze instead. These are just a few tips on iguana raising. Visit the library or bookstore for more information. Before long, you'll have your very own miniature Jurassic Park.