Why are reptiles cold-blooded?
Reptiles are frequently called cold-blooded, but that is a misnomer. In fact, body temperatures of some reach well over 100 degrees Fahrenheit, which is not very cold. (You would have a fever.) A more accurate term preferred by scientists is ectothermic, meaning reptiles depend on external heat sources to achieve high body temperatures.Ectothermic Vs. EndothermicEctothermic animals such as most reptiles, fish, and invertebrates require external heat sources to reach high body temperatures, and their temperatures fluctuate depending upon their environment. In contrast, endothermic (or warm-blooded) animals–mammals and birds–are able to maintain high body temperatures using internal metabolic heat production, independent of environmental temperatures.Heat SourcesThe primary heat source for most reptiles is direct and indirect solar radiation, which they receive by basking in the sunlight. Reptiles also receive heat from infrared (thermal) energy radiated from objects that are warmer th
