Keeping warm tomorrow, while I spend 15 hours outdoors?

Temps will be about 19 degrees F when I start at 6am, peaking around 31, then 20 when I finish at 9pm. I don’t have the best clothing for this (no heavy coat). My plan is jacket, two warm shirts, pants, kneesocks, two scarves (for neck and head), and carrying bottles of water (I don’t have a Thermos). Have you done this before?

(I’m working as an outdoor pollworker and canvasser for a Special Election, so I will be doing a little walking outside but mostly standing outside.) This isn’t cold enough to be dangerous in terms of health, right? What should I pay attention to and be careful of?