Brigham and Women's Hospital and the Dana Farber Cancer Institute, both based in Boston, are in dire need of Type O-negative blood, according to The Boston Globe.
O-negative blood is rare, with only 6 percent of people in the country having it.
The shortage also is attributed to a drop in donations during a bitter Midwest cold snap, Richard Kaufman medical director of the Brigham and Women's Hospital transfusion service, told The Globe.
While Brigham and Women's collects its own donations, the hospital heavily relies on other blood collectors.
"It's really everybody, every transfusion center, is being affected by this," said Mr. Kaufman.