The railing is heated by the sun, as the character leans against the railing, the molecules in her arm bounce back and forth with those in the railing making them the same temperature. This happens with DIRECT contact of objects.
Have you ever leaned against a hot railing? The transfer of heat from the railing to your arm or hand, is called conduction, this happens when the hot rail is heated by the sun. When your arm touches the hot rail the hot molecules meet the colder ones on your arm. The hot and cold molecules bounce back and forth until both of the objects are the same temperature.
This scene shows convection, transfer of heat without objects touching. The sun is heating the air directly below it, but as the hot air meets the ocean wind it becomes colder, but as the cold air meets land and warmer air it begins to warm again as well. This occurs in a repeating circle. Over and over again
This transfer of heat is called radiation. Radiation is heat passing through in waves. In this scene the waves of heat are coming from the fire to the hands of our character, without her touching the flames. This continues to happen unless something happens to the heat stop the heat from reaching your hands. (ex. the fire was put out from rain)