By Segun Adeyanju
Three brilliant teenagers from Indore, India, have created a game-changing solution for rural healthcare — a salt-powered mini refrigerator that works without electricity.
Called Thermavault, the invention could revolutionize how vaccines and medical supplies are delivered to remote areas.
The trio — Dhruv Chaudhary, Mithran Ladhania, and Mridul Jain — were inspired by the challenges their families faced in the medical field during the COVID-19 pandemic.
They discovered a cooling method using salts that absorb heat when dissolved in water, maintaining ideal temperatures for vaccines and even transplant organs.
After testing over 150 salts and hitting roadblocks, they turned to their science teacher, who suggested a blend of ammonium chloride and barium hydroxide octahydrate.
This combo gave them two reliable cooling options — one for standard vaccines and another for colder storage needs.
The boys’ invention won them the 2025 Earth Prize and $12,500, which they’re using to build 200 Thermavault units for testing in 120 hospitals.
The refrigerator is simple: a copper-lined box with saltwater poured between its insulated layers. It requires no power — just heat to recycle the salt for reuse.
“This will be incredibly useful in remote villages,” said Dr. Pritesh Vyas, who tested the prototype in Indore’s V One Hospital.
The teens are now seeking WHO certification and a patent, with hopes of global distribution through organizations like Gavi.
Thermavault may be young, but it’s already changing the temperature of global health.
