Back at Hanford we had enviro suits made from Tyvek, I believe we were allowed to used them as level B. Anyways, one of the procurement dudes found a huge lot that were a pastel yellow color for cheap. We found out why when we started using them in warmer weather, and the local apiary residents decided we needed a good pollinating. Apparently the color and intensity were a pavlovian trigger for the bees, as well as hornets, wasps, yellowjackets and a bunch of other critters. Needless to say, we opted to use them only during the dormant 1/3 of the year, and got the regular white ones at the higher price. Nothing like fighting off a gaggle of stingers while you are trying to run the probe down the glowing tank hole...

Something else anecdotal about the white suits; when we used them along with SCBA, they didn't always vent so well, and we nicknamed them the "Michelin Man" suits as they would inflate like Violet Beauregard after chewing the Wonka meal gum. Good laughs then.

I can attest that wearing the tyvek suits did provide an effective means of staying warm in bitter cold winds in December. On one training session, we transited a field in 20 mph average winds at 27 degrees. Under the suit I was wearing a tee shirt and jeans (and SCBA) and still managed to break a sweat before reaching the training station. On the way back to the changing factilty, we had doffed the SCBA and opened the Tyvek envelope, and that cold north wind fairly froze us for certain.

Tyvek is effective weather barrier, it is lightweight, and it is cheap. That makes it good survival provisions I would reckon.