Heat distribution unit. The Heat Distribution Unit (HDU), also known as a Heat Interface Unit (HIU), provides domestic hot water (DHW) and space heating to properties that are serviced from district heating or centralised boiler plants.
Called hypoglycemia, this deficiency of glucose in the blood is considered critical at, or below, 40 milligrams of glucose per deciliter of blood, or 40 mg/dL. However, this figure must be adjusted individually, as the exact level at which an a person develops symptoms varies.
A glucose level that is higher than normal may mean you have pre-diabetes or diabetes: 1  A 2 hour value between 140 and 200 mg/dL is called impaired glucose tolerance.  A glucose level of 200 mg/dL or higher is used to diagnose diabetes.