It's winter in parts of the world and Mother Nature has made this winter one of the worst.
While some dogs and even some cats have heavy, thick coats, most do not have sufficient protection from harsh winds, below freezing temperatures, ice and snow. Older pets and puppies and kittens may not be able to withstand the cold.
There are dogs that are equipped to withstand icy winters and even prefer to be outdoors. But even these dogs need some protection. Keep in mind that wet fur loses its ability to insulate. Dogs that prefer to be outside should have a dog house for protection. Place the house where it will be protected from the wind. It should be waterproof, have a sloping roof and should not sit directly on the ground. There are even doghouses that provide heating. Any heating source should be made specifically for animals to avoid accidents. You can also provide a place in your garage (make sure there's no anti-freeze around) or a shed to shelter your pet. Make sure your dog has fresh water available and check to be sure it isn't frozen.
You can provide a litter box for your cat and keep it indoors. Cats are safer inside in all circumstances. You can offer feral cats some type of shelter, a dog house, your garage, a shed or even a cardboard box placed in spot away from wind. Cats seek warmth in the engine of a car, so bang on the hood of your car before starting it.
Dogs need to go outside to potty. Try to keep these outdoor trips to a minimum and shorten the time spent outdoors.
There is clothing available for pets to protect them from cold and wet. Wool sweaters and jackets can provide some protection from the cold. Waterproof raincoats, some lined for warmth, can help keep your dog relatively dry while outdoors. Since dog's temperatures are regulated through the soles of their paws (and tongues), booties made especially for them will help against the cold and also protect their paws from ice and products like salt used to melt ice. When walking your dog on dark days, you should both wear reflective clothing to keep safe.
There are things you can do indoors to make your pet more comfortable. A pet pillow or a pet bed provides protection from the cold floor. Likewise mats and / or rugs and carpeting. My dogs prefer sleeping on the couches even though they have beds. I'm a softy and I allow it.
Check with your vet about increasing your pet's food during the winter months. The extra calories will help keep your pet warm. Just don't let your pet get too pudgy.
If you suspect your dog or cat is suffering from the cold (frostbite, hypothermia) contact your vet immediately.
And a cuddle with your pet will keep you both warm.
Note: If you keep other pets in outdoor cages, like rabbits, ferrets, etc., make sure they are protected from the elements. Consider bringing them indoors during the coldest time of winter.