This is because when water is heated to its boiling point of 100degrees celsius, more energy is usually needed to convert the liquid to gas so the additional heat helps in this conversion.
Water temperature doesn’t change when it reaches the boiling point till all the water evaporates into the atmosphere. When there is no more water, the temperature increases according to the nature of the container.
Humans get there energy primarily from glucose I believe. We break down glucose to get ATP (Adenosine Triphosphate) which is then used to supply energy to our cells in order to function.
