In drone transport every gram comes off the range, so the box and the source of cold are kept small. In a trial at Cyberjaya, Malaysia (PLoS One, 2022), 8.15 km flights of 17 minutes were flown with a 1.55 kg load and ice packs at 24.5 °C ambient. Mean kinetic temperature was 4.70 °C in an EPS foam box, 11.46 °C in aluminium and 14.17 °C in polypropylene plastic.
A temperature difference costs something even on a short flight. A Johns Hopkins team flew 84 samples for 3 hours over 258 km in an actively cooled box; the flown samples stayed on average 2.5 °C cooler than those left on the ground, and glucose showed an 8% bias and potassium 6.2% (Am J Clin Pathol, 2017). The team measured temperature on the way to the flight field as well.
What the record must cover
A data logger goes inside the box, and the record ends when the laboratory takes the sample over. Preparation, take-off, landing and receipt times go on the same record with the names of sender and receiver. If the wait on the ground is longer than the flight, that wait is what warms the box.
