Agreed. Not for this case, at least. Visible light might heat the room, but it doesn't heat the case of the CFL. Your heat loss, at least as it affects overheating the CFL electronics, is based on the amount of inefficiency, not the total input power.
It's very obviously a convection effect too (i.e. orientation sensitive, which radiation won't be). Try running two high-power CFLs for a while, one up and one down, then measure the case temperatures.