There are many “standards” for calculating wind chill, some online calculators think it is warmer at 225 kmh than 125kmh at 6c. I found this one which comes from the Australian Antarctic Data Centre:
6c at 80 is -5.4c
6c at 100 is -6.2c
6c at 125 is -7c
6c at 145 Is -7.6c
8c at 80 is -2.2c
8c at 100 is -2.9c
8c at 125 is -3cc
8c at 145 is -4.2c
8c at 225 is -5.8c
Of course these wind speeds are simply for comparison but highlight the importance of wind resistant outer layers in cold weather, sure your leathers might be wind resistant, but how about the zips and the flex panels, and your neck?
I’ve been wearing a wind proof onesie for seven years and a wind proof under jacket for more than 10. In the last few months I’ve also been wearing a duck down quilted jacket under the windproof jacket then the onesie under that with a wicking layer on my upper and lower body then a merino layer on top of that and an acrylic upper as used by deep sea divers in the North sea for use under dry suits. Plus a synthetic neck warmer. If it gets even colder I’ll wear a thin acrylic balaclava. Colder than that? Add an extra merino upper and a wind proof neck sock too in addition to all the above. Colder still? Fuck it, I’m staying home 🙂
Oh, and thin cotton socks then thick wool socks. Sure heated grips too, goes without saying.
Reading the AAD and other sites: onset of hypothermia is similar to heat stroke, you start to lose conscious thought, and you likely won’t notice. Gear up for the conditions! And for the gold standard, heated gear.