When letting your indoor dog out to go to the bathroom be sure to go out with them- when you are cold and ready to come in, they are cold and should come in as well! Be sure to wipe your dogs paws so they don't have any salt or chemicals on them that they may ingest and inspect them as they can get ice balls stuck between their pads that can quickly lead to painful frostbite. Lastly, putting a sweater on your short haired dog is a good idea but remove if it gets wet as this can lead to skin issues if the water gets trapped against their coat and skin.
With the temps being below zero recently and getting in the -20F + in the next few days, be aware that your outdoor dogs and cats will feel that bitter cold as well. Be sure to have a proper shelter for outdoor animals and bring them into the garage if needed. If they are not used to living in the house it is actually better for them to be in a garage or other enclosed structure with temperatures between 20-55 degrees as the abrupt change in temps from living outside in sub-zero temps to 70 degrees in our homes can be hard on them and can trigger upper respiratory issues. Also, be sure to keep fresh water in a heated water bowl so they stay hydrated- eating snow and ice is not sufficient for meeting their hydration levels.
A shivering animal is a cold animal; be sure to keep them sheltered and have proper beding/heat lamps if necessary! Have a safe Weekend!