How does the system and the environment outside a system change after an endothermic or exothermic event?

In an endothermic event, the system absorbs heat from the surroundings, causing the temperature of the environment to decrease, while the system's internal energy increases. Conversely, in an exothermic event, the system releases heat to the surroundings, raising the environment's temperature and decreasing the internal energy of the system. These energy exchanges can lead to changes in physical states, reactions, or temperature gradients in both the system and its external environment.