How do you stay warm wearing a dress and open toed shoes for nice/fancy occasion when it’s winter outside?

Yes the occasion will be inside but I’ve got sleeveless, above the knee dresses with open toed shoes!

I’m clueless when it comes to fashion. My mom said a shawl but she’s like 68 years old so I don’t consider her advice to be..... up to date.

How do I stay warm and still look sexy/fashionable?

Are stockings in? Should I find closed toed shoes? A shawl? Sweater?

I have no clue!