First, read the English article below.

When you are in bed, wrap your feet in a blanket and make sure that it is tucked all way round your feet to keep them warm. This will insulate your feet better than just draping a blanket over them. Zip your sleeping bag all the way up so that your feet are cocooned in the bottom of the bag. You lose a lot of heat through the soles of your feet on cold floors. When possible, keep your feet up on a couch or on a foot stool. Even if your home and workplace are dry and warm, you can get cold, wet feet when traveling between the two. Keep an extra pair of socks and shoes at work to switch into in case your feet get wet on the way.  Consider keeping “professional” shoes at the office and wearing insulated boots back and forth between work and home. If your office or workplace is cold, you can also find professional shoes with higher sides or thin layers of insulation to help keep yourself warm at work. Wearing wool socks with your standard professional shoe would be another option. If your body is covered up and your feet are still cold, it may just be that the room is too cold. Make sure all the windows are closed, put on central heating or light a fire, or buy a draught (draft) excluder if you think the coldness is coming from underneath your doors. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Giữ ấm chân trong khi ngủ. Không để chân xuống sàn. Chuẩn bị thêm tất và giày. Làm ấm phòng.