THERMOREGULATION

1. conduction - heat escapes from your body when you sit on a cold rock.
2. convection - cooler air currents remove heat from the surface of your skin.
3. evaporation - evaporative cooling occurs when water (often from perspiration) leaves the skin surface as a gas, lowering the body temperature by cooling blood vessels in the dermis.
4. radiation - e.g. acquisition of heat from solar radiation (e.g. snakes "sunning" on a cold day).

Types of thermoregulation

There are two types of thermoregulation that are used by animals:

1. physiological regulation: This is when an organism changes its physiology to regulate body temperature. For example, our body tends to sweat inorder to cool our body down. Another example is when our bodies get cold, it likes to shiver so that the body can create some heat.
2. behavorial regulation: This is when an organism changes its behavior to changes it body temperature. For example, when your body starts to get hot because of the sun, you may want to find a shade to cool yourself down.

Physiological temperature regulation in vertebrates

Ectotherms

Even though fishes are ectotherms some have developed the ability to remain functional even when the water temperature is below freezing and some even use natural antifreeze to resist ice crystal formation in their tissues; amphibians (also ectotherms) must cope with the loss of heat through their moist skins by evaporative cooling; reptiles, like amphibians must warm their bodies by behavioral adaptations; the stratum corneum they possess limits heat loss by evaporative cooling.

1. behavioral adaptations like living in burrows during the day and being nocturnal
2. evaporative cooling by perspiration and panting
3. storing fat reserves in one place (e.g. camel's hump) to avoid its insulating effect
4. elongate, often vascularized extremities to conduct body heat to the air.

Behavioral temperature regulation

In addition to human beings, a number of animals also maintain their body temperature by physiological and behavioral adjustments. For example, a desert lizard alters their location continuously during a day. In the morning, some portion of its body, which is head, emerges from its burrow and later the entire body comes out of its hiding place and basks in the sun to aborb solar heat. As the sun gets stronger, a lizard hides under the rock or goer back to the burrows. Interestingly, as the sun goes down and the temperature is cooler, it emerges again.

By changing its behavior, a lizard can keep the body temporature to some degree. However, since a lizard is an ectoderm, she is not able to control the body temperature through metabolic regulation.

Some animals living in cold environment maintain their body temperature, preventing heat loss. They let their fur grow more to increase the insulation. Some arctic animals allow their body extremities to cool to very low temperature. Compared to the core body temperature, their legs or nose are extremely low nearly zero celsius, so they have nothing to lose heat in legs or nose. Because the extremities are not insulated well, high temperature in foot and hooves is hard to maintain.