Self-regulating thermostat

Normally, a chicken's body temperature is 104-107 degrees F., but it can vary greatly depending on the temperature of the environment. In cold weather, a chicken's body temperature can drop down as low as 73 degrees F. before death occurs. Unfortunately, there is much less flexibility on the other end of the scale. The upper lethal limit on body temperature is 113-117 degrees F. Since that's just a few degrees above normal, the chicken must be able to get rid of excess body heat quickly.