What folks don't realize is that it's all a matter of keeping skin temperature at an optimum for comfort. Radiant heaters can heat the skin directly, but if they don't have enough surface area, the concentrate the heat into hot spots. Convection heaters, on the other hans, have to heat the air which, in turn , warms the skin.
The skin will lose heat, through radiation to any cold surface it faces. Which is why the easiest way to stay comfortable is often to
simply block off those cold surfaces with things like drapes.
If anyone's interested in the subject of thermal comfort,a Danish engineer named Fanger has done a lot of work in the field. Googling "Thermal Comfort" can be an instructive exercise.