First, read the English article below.

For conventional mattresses that don’t have a designated top and bottom, turn the mattress over so you're sleeping on the other side. For mattresses that do have a designated top and bottom, rotate the mattress 180 degrees. This will ensure even wear over the surface of the mattress. You should flip or rotate your mattress every three to six months to ensure even wear. A mattress protector is a plastic case that you can use to keep your mattress safe. You slip the case over the mattress like you would with a duvet and duvet cover. Then close the zipper to seal the mattress and protect it from spills, dust, dirt, stains, and even bed bugs. There are also mattress pads and covers you can buy to protect just the top of the mattress from spills and dirt. When the mattress is clean, dry, flipped, and protected, you can make the bed with your clean linens. Start with the fitted sheet, followed by the top sheet. Put the pillows back in their cases, and return all pillows, blankets, and decorations to the bed as well. Feel the mattress all over before making the bed to check for moisture. If you encase a damp mattress in linens and blankets, it won’t dry out and you'll have mold growth. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Lật hoặc xoay nệm. Dùng bọc bảo vệ nệm. Trải lại giường.