The time of the measurement. We can get warm near a fire without actually crawling into it. In fact, there is the problem that the parts of you that don't face the fire tend to get cold while those that do face the fire can get overly warm. The movement of heat is accomplished by radiative transfer in these cases. Devise a demonstration using this equipment to show that the heat is being carried by radiation and not some other mechanism.
Convection is a very powerful heat transfer process that is generally confusing.
This may be due to the fact that any convective transfer of heat usually involves a conduction process at either end. The device set up here illustrates all the features of convection with most of its subtlety. Examine the setup carefully and determine why the temperatures are as you observed them. It will be helpful to remember that warm air tends to rise when surrounded by cooler air. So now let's apply this stuff to the refrigerator.