We recommend: Evursua Kitten Sweater
Another way to help keep your kitten warm is through kitten clothes. A nice sweater will go a long way towards helping the little one deal with the cold especially in very cold weather.
When shopping for these clothes, the fit is everything. Too tight and the kitten will hate it. Too loose and you will miss out on the warming benefits. Just follow provided measuring guidelines to pick out the perfect size for your kitten.
The material also matters a lot. You want to settle for something that is soft, warm, and still breathable. Durability may not matter too much especially with very young kittens as they will soon outgrow the clothes. However, it is worth considering for more mature kittens heading into adulthood.
With this in mind, polyester, cotton, and knitted wool are perfect for kittens.