The American Red Cross announced a national blood supply crisis on Monday. This marks just the second occurrence in its history. Blood donations plummeted to the lowest summer levels seen in four years.

Typically, blood shortages arise during summer as donations decline. Vacation time and increased outdoor activities contribute to the drop in donations. Additionally, more injuries occur, raising the need for blood supplies.

This year, extreme heat, poor air quality, and the spread of foodborne illnesses further impacted donor turnout. The American Red Cross is calling for increased donations to address the crisis.