Cats will get cold if they aren't covered with blankets in winter. The ideal temperature for cats to live in is between 25 and 29 degrees Celsius. When the temperature drops below 10 degrees Celsius, cats will feel cold. However, the general way to keep cats warm is not by covering them with blankets, but by maintaining a comfortable and constant indoor temperature. 
How to create a warm and comfortable home for your cat:
1. Place an extra soft blanket inside the cat bed to enhance its warmth.
2. Lay a rug in a sunny spot in your home so your cat can sunbathe warmly, and try to minimize the time your cat spends outside.
3. If the cat's bed has windows on all four sides, you can close some of the windows to reduce the amount of cold air entering.
4. Prepare a small heater for the cat to keep warm, or you can adjust the temperature of the whole house by turning on the heating.