Blood donors are being asked to step up. There was a nationwide critical blood shortage earlier this summer. Bobbi Snethen with the American Red Cross Badger Hawkeye Region said that was resolved, but the massive heat wave led to a decrease in donations and cancellations of some blood drives. “We’re still building the blood supply up to adequate levels, however we still remain at seriously low levels,” said Snethen. Anyone eligible to donate can help out, although specific blood types are the most sought after. O-negative, B-negative and A-negative blood types can be transfused to more patients. At any given time, only about 38 percent of the population is eligible to donate, and the Red Cross estimates only eight percent of those actually do so. On average, there’s a need for 500,00 units of blood a day in the region, serving much of Wisconsin, parts of Iowa and U.P.