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.
Different practitioners use different standards for determining whether your level is too high. Some will say that if your one-hour blood sugar level is 140 milligrams of glucose per deciliter of blood plasma (mg/dL) or more, you need to have the glucose tolerance test.