For prolonged use, place your MacBook on a flat, stable surface. Do not place your MacBook on your lap or other body surface for extended periods of time. Prolonged body contact can cause discomfort and potentially a burn. The bottom of the MacBook case functions as a cooling surface that transfers heat from inside the computer to the cooler air outside. The bottom of the case is raised slightly to allow airflow, which keeps the unit within normal operating temperatures. In addition, warm air is vented from the slots in the back of the case.