In eight hours. It is not recommended to store health stickers for a long time, and the longest time is no more than eight hours. If it is stored for a long time, it is easy to breed bacteria. The thermos cup should be cleaned after each use to prevent infection. Vacuum cup Vacuum cup is usually a water container made of ceramic or stainless steel and vacuum layer, with a cover at the top and tight seal. Vacuum insulation layer can delay the heat dissipation of water and other liquids to achieve the purpose of insulation.