I would venture a guess that most of us who consider fire starting items essential live in or near wooded areas that are also subject to drops in temperature (myself included, and YES, I do consider fire starting items essential kit items). I also consider shelter items essential for the kit as well, and place it's priority just slightly above the fire starting items. All that said, your scenario where there is no wood or other fuel available has given me quite a bit to think about.

In situations where fire is not possible or not advisable, I have to agree with others about bringing along a stove with fuel, and would also suggest including some of the various hand warmers available if there is room. These can be activated and placed in strategic spots (like under the armpits) to keep you warm.

BTW, welcome to the forums Vasco.