The Summerville Medical Center and Trident Medical Center will host emergency blood drives from 11 a.m. to 3 p.m. Friday in the Summerville Medical Center's cafeteria and at the front entrance of Trident Medical Center.

"Currently, we are at critical levels for all blood types, especially O negative and O positive," said Sandy Wallace, medical technologist with Summerville Medical Center.

Those who donate blood will receive a complimentary T-shirt from the American Red Cross.

To schedule an appointment, contact Wallace at 832-5040 or Christal Joyner at 847-3376. Walk-ins also are welcome.