What does an endothermic reaction do

In an endothermic reaction. Instead of having an activation energy, you have to put in more energy than what is needed in the final product. If you draw an exothermic reaction energy vs time graph backwards, you'll see what I mean. Endothermic reactions feel cold because they take heat energy away from your hand. The heat comes from the surroundings. The heat energy goes into forming the new bonds in the reaction. In an endothermic reaction the bonds of the products are higher energy than the bonds of the reactants. This is why endothermic reactions absorb heat to begin with, they need the energy to form bonds.