Flowers

and.....

If you live in North America and they are annuals, you can cover them at night for about another month.

what flowers are they?

You can cover them when it is cold, but eventually, if you live where it gets really cold, they will die or die back if they are perennials. If they are perennials in pots, you could try putting them in your garage or the house for the winter. Pots are very susceptible to the roots freezing and the plant will die. If they are annuals, they will succumb to the cold to be replaced next year. Winter is coming and it is time for the plants to die or sleep underground until spring.