My bike shop told me to warm my bottle of Chain-L No. 5 in a pot of hot water then apply 1 drop per link. I started out doing the warming, but lately have been applying it at ambient garage temperature (40F). FB, is the warming necessary?
Not at all, the oil will penetrate completely at room temperature. Warming makes it faster, but not better.
In any case the temperature of the chain is more important, since the oil will quickly come to the chain's temperature. Warming the chain after applying makes it easier to wipe off the excess because it reduces the adhesion and viscosity.
So if you want to get involved with warming, think chain, not oil. Otherwise don't bother, but keep in mind that Chain-L has to be applied at room temperature (both the oil and the chain) or higher. Chain-L will not wick in effectively on a cold chain. So don't try applying it outside on a cold winter day.