Realizing that the October night time temperatures in Tibet will be somewhere between 20 and 30 degrees F, I decided early on that I would bring along a vest to complement my fleece jacket and a thick cotton sweater. Those three items would be my protection on cold nights. Only problem. I don't have a vest so here was another item to add to the purchase list.
Where to start? My friend Bob convinced me that I ought to get a down vest for warmth - forget all that man made stuffing, go for what Mother Nature perfected over years of evolution and you won't go wrong! Bob brought his North Face in and showed me how compact a size he could scrunch the vest down to. I'm sold.
With Bob egging me on, I searched on a couple of our favorite outdoor gear websites and found more vests than I could shake a stick at. Different colors, styles, etc. Which one to pick? When it comes to the important decision criteria, the differentiating factors seem to be fill power and what type of material the vest is constructed of. Since I will be taking a waterproof, windproof jacket with me, I eliminated the need for a waterproof vest. That left fill power.
Exactly what is fill power? Fill power measures the amount of cubic space that one ounce (or cluster) of down will fill. For example; one ounce of 750 fill power down will fill 750 cubic inches of space, one ounce of 550 fill, 550 cubic inches of space. The higher number, the warmer the vest will be. 550 fill is considered lightweight and good for temps in the 40-50 F range. At the other extreme is 900 fill which is hard to find and therefore, expensive- probably only need it for sub-arctic conditions! For my purposes, I think a mid-range fill power - somewhere in the 600-700 fill power range will suffice.
I had the camel blanket to keep me warm in the Wadi Rum in Jordan and now I will have the goose down to shield me from the cold in Tibet!