Although I've done my share of riding open tractors in Sask. winters moving snow or feeding cattle at -20F I'd have to say the coldest I have ever been is standing at farm auctions in spring or fall. Insulated suits, boots , toques, mitts, all fail after a few hours out in the wind. Just not moving around enough to keep the blood circulating. I get so stiff and miserable I lose all interest in buying anything and just hope my fingers are not too stiff to turn the key to start the truck and head home. 
Riding open tractors will chill the extremities but standing long term at sales just drops my whole body temperature.  

https://www.youtube.com/watch?v=aQY8GQd8p0U&feature=youtu.be