The quality polypro and capaliene long underwear lasts forever, I didn't bring any but maybe next year.
I did bring a $3 thrift store cashmere sweater, machine washable and thin and comfortable!! wore it under funkified outer layers, stays warm in the cold and cool in the warmer weather...it breathes, similar to real fur...much like the giant rabbit fur jacket one of my campmates swears by.
Sheep sheerling works similar, it breathes and keeps you warm.
I get very cold easily, fleece w/polypro/capaliene long underwear are good layer combos but real furs and cashmere work amazingly well and feel better.
I don't know the long list of taboo furs, probably fox, seal etc...everyone seemed ok with rabbit fur (jack rabbit?) and sheep skin uggs.
I brought a bunch of ski racing jackets and gave them away to wandering freezing cold burners at night. I painted the man symbol over the logos...one guy got a $400 Burton jacket and almost cried (so did I, it wasn't my size! shucks)...people just toss good ski clothes out up where I live...I collected them for a while for freinds and family, had too many so I stenciled the man on them after I read on eplaya that it get's cold at night at BM and brought them along to give away.
$3 space blankets, I used one of those from my emergency kit to help rescue a woman I didn't know stranded and in trouble out on the playa on man burn night, she got extra, seriously, severly trashed and needed to go to rangers/medical...odd but she was wearing a fox fur coat...anyway, the space blanket worked very well they told me. Next day I was told the woman survived, sanctuary helped her...if not for eplaya I wouldn't have known about sanctuary either...extemely professional folks there. Thank you to them for sure!!
Sorry for the huge ass post but I KNOW cold...space blankets; 3 lousy bucks and tiny packets, I keep them everywhere, truck, home, travels.
Edit for spelling, LOL
I'm the MAN in a truck, burner who is stuck, you're in luck! I'll whip out my BIG tow chain and not charge you, not even one lousy buck!