Lizards are cold-blooded and begin the day with a body temperature that is too low for much activity, and they must bask in the sun to increase their body temperature. While basking in the sun they stand sideways to it and flatten and tilt their bodies to maximize heat intake. They can ... spread their bodies and change their skin colour from light to dark to increase heat intake. However, in hot desert areas lizards run the risk of overheating and have also developed ways of losing heat.