How is this for a simple formula as a last minute
check to see if you have enough clothing insulation?

Tskin - Tmin [degF] = Clothing Insulation in Ounces

Tskin = average skin temperature ~ 85degF
e.g. for +30degF, 55oz = 3.4 pounds clothing
e.g. for -30degC, 115oz = 7.2 pounds clothing
The intent is enough clothing for prolonged periods of low activity, which might be twice the clothing required for fastpacking, but half the clothing needed to lay down and sleep in extreme conditions.

This is for top, bottom, hands, head, and socks, including 1 light shell, 2 if for puffy clothing, but not including heavy rain shells, or shoes and boots. Clothing must also be suitably lofty outdoor clothing, like non-cotton skin layers, wool and fleece layers, down or synthetic fill layers, all reasonably well fitting and evenly distributed. The idea is you could just get dressed in it all before you go and weigh yourself full loaded without shoes and rain gear, and subtract your naked weight. This would also be a good check to see if all the layers are fairly evenly distributed, and fit inside one another so as to be worn in any combination.

The real question is whether the formula is right. It depends mostly on what activity level could be sustained for prolonged periods of exposure to the extreme conditions. I figure this should be something in between a slow energy conserving trudge, and sitting down now and then. Perhaps 150-200 kcal/hr.

Of course people could adjust the formula to suit their needs.

An idea I had was that individuals could calibrate their formula by dressing some very cold night for a long slow walk, wearing what they felt was appropriate. Maybe after the first hour of settling in they could combine walk and rest to stay just warm enough, and then using some tables or heart rate monitor estimate their calorie consumption, so they could adjust the formula if they felt they were too active or inactive compared to what they felt they could sustain for prolonged periods in a survival situation.