Paige turns on an electric space heater in the center of her bedroom. The coils glow, and the room becomes warmer. How is heat reaching the corners of Paige's bedroom?

Think of it this way. Osmosis occurs when water flows to a different side given its a membrane or not. This is because it flows to a less dense area to reach equilibrium between the two sides. Heat is very similar. It will try to spread to places where there is not as much heat. Keeping the laws of heat travels up, the heat from the coils will reach the ends. We call this "Thermal Equilibrium"