A vac bed (short for vacuum bed) is a form of full body bondage, particularly popular among rubber enthusiasts. It consists of two sheets or a bag of latex, rubber or PVC, supported by a frame. A zipper or tape is used to seal the bed. Before the bed is sealed, a breathing tube is inserted into the mouth. Then an air pump or vacuum cleaner is used to remove the air from the inside of the bed, leaving the subject trapped between the sheets of plastic. In cheaper and most self made beds the vacuum cleaner needs to be kept running. Higher quality models seal well enough and have a valve at the air outlet that the vacuum pump can be turned off.
As with all activities that cover large portions of the body, it is important to watch for signs of overheating and dehydration.