thermodynamics - Does heat transfer actually from high temperature to low temperature?

Consider Object A which has a temperature of 70°C and Object B which has a temperature of 20°C. The objects are placed right next to each other.

Now, as far as i know, the temperature is defined as the average kinetic energy of the particles in a system. Again, as far as i know, there are particles colliding inside, resulting in a range of different speed and hence kinetic energy.

So if we are talking about the average kinetic energy, that means there are some high kinetic energy particles in object B (which has a lower temp) and there are some low kinetic energy particles in object A (which has a higher temp) right? If so, couldn't the high temp particles in object B transfer some of its kinetic energy to object A, resulting a temperature change?

Answer

Individual transfers of kinetic energy due to collisions can be the “wrong way round” but on average for many collisions there is a net transfer of kinetic energy from a hot body to the colder body ie there are more “hot to cold” transfers than there are “cold to hot” transfers.