A standard twin mattress is 39 by 75 inches. A king is 76 by 80 inches. This means that a headboard for a king bed is going to be about 76 inches or wider, plenty wide enough to go along the length of a twin bed. Headboards are often slightly wider than the bed for which they are made.
Hemoglobin, Hematocrit, Blood Count. In order to donate blood, a woman must have a hemoglobin level of at least 12.5 g/dL, and a man must have a hemoglobin level of at least 13.0 g/dL. For all donors, the hemoglobin level can be no greater than 20 g/dL.
Answers from Ruben A. Mesa, M.D. At one time, type O negative blood was considered the universal blood donor type. This implied that anyone â regardless of blood type â could receive type O negative blood without risking a transfusion reaction. But it's now known that even type O negative blood may have antibodies that cause serious reactions during a transfusion. And blood transfusions in general carry some risk of complications.