He had an impression that combustion and respiration are chemically identical. Lavoisier demonstrated this with the help of Pierre-Simon Laplace. They both carefully measured the amount of "carbon dioxide and heat given off by a guinea pig as it breathed".[7] Then they contrasted this to "the amount of heat produced when they burned carbon to produce the same amount of carbon dioxide as had been exhaled by the guinea pig".[7] Their conclusion made Lavoisier confident "that respiration is a form of combustion".[7] Also, the result showed that the heat mammals produce through respiration allowed their bodies to be above room temperature.