Metro Health is declaring a blood emergency in San Antonio. The severe winter weather has created a blood shortage in the area. Health officials say there's not enough blood supply for surgeries that require blood, or to treat trauma cases or emergency surgeries. Canceled blood drives and donor room closures have meant the loss of at least two-thousand donations. The South Texas Blood & Tissue Center is accepting walk-ins or donations by appointment. All donors will receive a 20-dollar Amazon gift card through Sunday.