The Red Cross issued an emergency call for blood donors on Friday, as its blood banks dip below the 5-day supply needed in case of a national disaster.
"Over past few months we have had 39,000 fewer donations nationwide than what is needed," spokesperson Natividad Lewis said.
"Blood products are being delivered to hospitals faster than donations are coming in, which is why it is an emergency call for people to come out and donate."
Lewis explains that fewer people donate blood in the summer, when many go on vacation, and universities are closed.
According to US regulations, blood donations must be transfused within 42 days. Platelets must be transfused within five days.