What is a characteristic feature of endothermic reactions during their occurrence?

Endothermic reactions are characterized by the absorption of heat from their surroundings, which leads to a decrease in the temperature of the surrounding environment. This means that during the reaction, the energy required to break bonds in the reactants is obtained from the heat in the surroundings, causing the immediate environment to feel cooler. This cooling effect is a distinctive feature of endothermic processes, making it a key indicator that an endothermic reaction is occurring.

In contrast, the release of gas bubbles or emission of light can be associated with other types of chemical reactions, such as some exothermic reactions or gases released during reactions in general. Similarly, changes in pressure may occur in various reactions but are not a defining characteristic of endothermic reactions specifically.