In my exercise classes: person A was on the floor facing the ground?
She didnt. She could be mistaking something scientific for something spiritual. For instance, if you are outside, you can feel the sunlight, you can also tell when there is a shadow on your arm because of the change of temperature in that spot, even if your eyes are closed. That is not an illusion or magic as your skin is literally just feeling the change in temperature due to the lack of sunlight on that particular spot of the arm. People can also sense the body heat of others, even when they are not touching. This is because the heat from the skin is slowly being dissipated though the airs circulation. But the body is constantly producing heat, so this affect doesnt really ever end. If a person is touching the air close to the other persons skin, then they could feel a slight change in temperature as the air around the other person is slightly increasing in temperature due to the persons body heat. This affect is not as noticeable if the person is moving rapidly, not allowing the same section of air to be heated to a noticeable degree. When your teacher said that person A could feel person Bs energy, that was a lie as the teacher couldnt have known whether or not person A was really feeling person Bs energy at that moment. But in a sense, person A could feel person Bs HEAT ENERGY if person Bs hand was close enough.