Heterothermy is an animal that is normally hme and endo, actively and intentionally reduces its body temp. Aquatic poikilotherms take on the temp of their environment. Terrestrial pokilo can change their body temp by behavioural regulation. This animal is using behaviour means to keep body temp relatively constant and at a diff temp than the air. At night it"s the same temp as the burrow its in. Lizard model body temp has a higher range, bc it picks up the temp of the environment. The actual lizards kept their temp more regulated. Moving into sun, climbing trees, exposing body to wind to regulate temp. Adjust temp to induce a fever state to fight off infection. Body increases temp to kill invading pathogens. Disadvantage is if its too high humans cant tolerate it well, but the purpose id to kil off pathogens. Causes lizards to seek out hot temertatue, to raise body temp to kill off invading bacteria.