3-season layering system from scratch (Nunatuk, Melanzana options; others?)

Thanks Richard, your anaylsis and table is super useful. Have you done any (or do you know of any) research into the efficiency and heat loss of different parts of the body? People like Sean are trying the 5.6oz body and 2.5oz arms, obviously vests are popular, etc.. I’m curious about whether these systems actually work out more warm-for-weight.

Vest gives slightly faster thermo-regulation only

This is why I keep coming back to BPL :)

“2C = 35.6F; the 800 fill down needed for thermo-neutral (TN) camp chores over 1 clo base is ~3.5 oz of 800 fill or ~2.4 Iclo.

Camp chores have an average MET of 1.75; resting aka BMR has an average MET of 1; and sleeping has an average MET of .8.  The MET rate is inversely proportional to the Iclo needed to be TN.”