Yes, Dreadbelly, the thing that is wrong is that
30 MPH wind blowing 15 degree air through
a single layer of wool takes more energy
to overcome than my metabolism can manage.
(Box pleats don't always stay "stacked" when
the wind blows, particularly if I am walking.)

The knife pleated tank puts more layers between
my legs and the icy blast. I haven't tried it
yet, but I can probably also sit directly on the
ice, and not get cold.