Heat loss refers to the process by which heat is transferred from a warmer area or object to a cooler one, resulting in a decrease in temperature. This can occur through various mechanisms such as conduction (where heat flows directly between two objects that are touching), convection (where heat is transferred through the movement of fluids like air and water), radiation (where heat is emitted from a hotter body to a cooler one without any physical contact) or through evaporation/condensation. Heat loss can be desirable in certain situations, such as when trying to cool down a room during summer by opening windows and doors to allow for air circulation. However, it can also lead to energy waste if not properly insulated or regulated, resulting in increased heating costs and discomfort.