Buddhism makes a distinction between physical （clinical） death and mental death， with the former preceding the latter by a period of some three to eight hours. Actual death is defined as the moment when the Alaya consciousness leaves the body -not when the heart has stopped or brain waves can no longer be detected. This is the reason for the waiting period of at least three hours after clinical death before the body is disturbed， as taught in Mahayana Buddhism， particularly the Pure Land and Tantric schools. Many hospitals nowadays recognize these beliefs and are prepared to meet the wishes of bereaved families and relatives.