The American Red Cross says it desperately needs more people to donate blood.
The agency says its supplies are now at emergency levels, with 50,000 fewer blood donations than expected so far this month.
The Red Cross says all blood types are welcome.
But there's a particular need for O positive, O negative, B negative and A negative to meet expected patient demand this summer.
Type O negative is the universal blood type and can be transfused to anyone who needs blood.
Everyday, the Red Cross must collect more than 17,000 pints of blood for patients in need across the country.
To learn how you can donate, visit www.redcross.org.
KMPH News partner CNN contributed to this report.