Why our body cells cannot use heat energy?
Amphibians are ectotherms. This means that they derive body heat from their surroundings. Like reptiles and fish, but unlike mammals and birds, amphibians do not need to consume food to generate metabolic heat. Instead, a large percentage of the food they consume is used directly for growth and reproduction. Source: http://www.houstonzooblog.com/frog_blog/amphibian_biology/index.