One of the most obvious explanations is that the air molecules are hotter because they come in direct contact with the oven's heat source or scorching interior walls. Another significant reason is that the meat's colder interior absorbs heat from, and cools, the warmer surface. As the meat's internal temperature increases during cooking, this cooling influence diminishes in importance.
A third major factor, evaporation, is less apparent. As the meat cooks by dry heat, some of its internal juices flow to the surface and evaporate. This ongoing process produces a cooling effect. (When water evaporates, it cools the surrounding area because the change from liquid to gas requires heat calories). For this reason - and because animal flesh is a less efficient conductor than metal - you can briefly touch a roasting meat but not the pan in which it sits.
** Asian Recipes