Final answer:
The man is assuming that heat would be transferred through the door by conduction. When he feels the door, he is checking if it feels warm, indicating that heat from the fire has been conducted through the door.
Step-by-step explanation:
The man is assuming that heat would be transferred through the door by **conduction**. Conduction is the transfer of heat through direct contact between objects or substances. When the man feels the door, he is checking if it feels warm, indicating that heat from the fire has been conducted through the door and it may not be safe to open it.