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.
Level constancy is accomplished primarily through negative feedback systems, which ensure that blood glucose concentration is maintained within the normal range of 70 to 110 milligrams (0.0024 to 0.0038 ounces) of glucose per deciliter (approximately one-fifth of a pint) of blood.