My ski jacket keeps me warm at -8 in the Alps, with just a T shirt underneath, but strangely in the UK, with all that dampth (which is turbo damp), I need a fleece as well.
In Alps (or Colorado/Alberta), I’ve very rarely felt the cold down to -20c.
Yet I felt cold (in more ways than one) during that second half against Newcastle. Always cold at football matches in the winter, with ski layers on.
Put it down to the damp maritime cold …. goes through to your bones.