Suzy, let me describe Eric at -6 deg C:-
Full thermal underwear
Flannelette shirt
Trackydac trousers
Perhaps pair of jeans over trousers
Explorer socks
Heavy waterproof boots with inner fleecy liner
inner fleecy vest
Outer heavy cotton vest with lots of pockets
Heavy parka
woollen scarf
fur flying helmet
inner thermal gloves
outer heavy fur gloves
And having a great time with scope with heaters on full and a crystal-clear sky!
As long as my toes don't get cold, and I can blow my nose, I'm fine.
All part of the fun!