Here's why:

* Conduction is the transfer of heat through direct contact between substances.

* Hotter objects have molecules that are vibrating more rapidly, with more kinetic energy.

* Colder objects have molecules that are vibrating slower with less kinetic energy.

* When these objects touch, the faster-moving molecules of the hotter object collide with the slower-moving molecules of the colder object, transferring some of their kinetic energy. This transfer of energy is what we perceive as heat.

So, the direction of heat flow during conduction is always from the area of higher temperature to the area of lower temperature.