Radiant heat is the least effective type of heating.
Convection occurs when a liquid or gas is heated, it is the transfer of heat by the physical movement of the heated medium itself.
An electric/gas heater with a fan is a good example, Convection heats the air and is slightly more efficient than heat radiation.
Conduction is when there is physical contact between the heated medium and the object that we wish to heat, conductive heat is the most efficient of the three forms of heat transfer.
|rocket mass heater with the chimney incorporated as a cob bench for direct contact and thus conduction.|
A Rocket mass heater is an excellent example of energy efficient heating.
So bodily contact with the heat source is by far the best method and it can be as simple as putting an electric blanket on the sofa or as elaborate as building a rocket mass heater.