A type of chemical reaction that absorbs heat energy is called an endothermic reaction. In an endothermic reaction, the system takes in energy usually in the form of heat from its surroundings, resulting in a decrease in the temperature of the surroundings. Common examples include photosynthesis in plants, where sunlight is absorbed, and dissolving certain salts in water, which can feel cold to the touch. Such reactions are crucial for processes that require energy input.