During a vaccination drive in a rural health centre in Madhya Pradesh, you discover that the oral polio vaccine (OPV) vials stored in the vaccine refrigerator have been kept at 4°C instead of the recommended 2–8°C range. The temperature log shows the refrigerator has been running at 4°C for the past 3 days. The vials are still within expiry and show no visible discoloration. What is your most appropriate immediate action?