Some things you should know about heat...
We've heard this before, "heat rises". But this is not true for radiant energy. If it were we would need to put heat lamps on the floor and the earth (preferably the side you're standing on) would always have to be above the sun. When you put it in those terms heat rising becomes a silly thought, agree?
One of the major methods your body regulates its internal temperature is by the flow of blood to the skin.
When your body is exposed to a warm to hot surface it prevents your body from releasing heat via radiation and it may absorb energy in the form of heat - both which make you feel warmer.
When your body is exposed to a cooler surface you release energy which takes away heat which makes you feel cooler.
A warmer or cooler surface in a building is based on its energy efficiency and/or by "conditioning" the surfaces with PEX pipes or other forms of radiators.
The less efficient a building the greater the temperature difference between your skin and the temperatures of the walls, windows, doors floors and ceilings.
It is the temperature differences between you and the building which in part, causes discomfort.
That's why conditioning surface temperatures is so important in the comfort equation.