While we usually associate bumblebees with summer, they can sometimes be found in winter.
If you find a bumblebee in winter or in bad weather, it's best not to take it into your home. If it is a queen bee (you can tell that it is a queen if it's quite big), she will need to be outside to search for a nest. Indeed, she may already have a nest that she is gathering food for. Bumblebees can cope quite well with the cold if they have enough energy. While they get most of this energy from nectar in the flowers, this isn't always available in winter.
You could help bees like these by putting them somewhere sheltered in your garden. You could also feed bumblebees a mix of sugar and water. Click here to read more on how to do that.
If you find a bumblebee in your home, you can put it outside in a sheltered place, even if the weather is bad. Bumblebees only have a limited life span, and they need to be outside to complete their life cycles, so it's best to let them out to do that.