Answer:
radiation
Step-by-step explanation:
Based on the scenario being described in the question it can be said that the type of heat transfer that is being modeled is radiation. Like demonstrated in the picture attached below, radiation involved the transfer of heat through rays, waves, or particles as opposed to fluids or gases. Which is what is happening in this scenario, since the individuals are building up heat by moving and that heat is being passed on to the individuals around them through waves.