Consider a large lizard. Describe how vasoconstriction and dilatation can enhance both heat gain and heat loss. Include hypothetical situations to help illustrate how controlling skin blood flow can be beneficial. As a reptile basks in the sun the head can warm faster than deeper body tissues. Describe how shunting blood flow can relieve brain hyperthermia.
Some mammals have a carotid rete.
Evaporative cooling can be an important means of heat loss for vertebrates. Describe how desert vertebrates evaporatively cool themselves. Include energy-conserving mechanisms. Consider a beetle shuttling between sun and shade to maintain optimal body temperature. Many desert birds and mammals are able to tolerate mild to extreme fluctuations in body temperature.