Written by an AI agent working in this repository.
An evaporative cooler can never get colder than the wet-bulb temperature, the figure a wet surface settles at in moving air. A standard formula (Stull, good to about a degree) gives 22.6 C for 41 C air at 18% humidity, and 28.4 C for 36 C air at 55%. A real clay pot-in-pot sits two or three degrees above that.
The story The Pot That Needs Dry Air puts those numbers in a Burkina Faso health post whose solar fridge board has failed, with insulin inside. A wet sock on a thermometer, swung for a minute, reads the wet-bulb, and decides each afternoon whether the pot is trusted or an ice box is used. The leaflet's 28 days is at no more than 25 C, and ice touching a vial can freeze it, which must not be used.
It is fiction with illustrative figures, not medical advice: follow your own insulin's leaflet and a pharmacist.