San Luis Obispo, CA -- A local ice cream shop is doing its part to get people to roll up their sleeve and help out our local blood banks. Doc Burnstein's Ice Cream Labs will be giving a certificate for a free pint of ice cream to all blood donors between now and August 15. According to KSBY, United Blood Services has seen a shortage in blood since the July 4th Holiday weekend. While all blood types are needed, they're reaching out to people with O-Negative blood. That is considered the universal blood type.