Three Indian teens just revolutionized healthcare in remote areas with a fridge that runs on salt—no electricity needed! Dhruv Chaudhary, Mithran Ladhania, and Mridul Jain, students from Indore, India, won the 2025 Earth Prize and $12,500 for their invention, Thermavault. This isn’t just a science fair project—it’s a lifeline for villages struggling to transport vaccines and medicines without reliable power.
The fridge uses a clever saltwater trick: when certain salts dissolve, they suck heat from their surroundings. After testing 150+ salts (and nearly giving up!), their teacher suggested ammonium chloride and barium hydroxide octahydrate—two salts straight from their ninth-grade textbook. The result? A reusable cooling system that keeps vaccines at 2–6°C (perfect for most medicines) or even sub-zero temps for organs. Just boil the saltwater to reset it—no freezer required!
Imagine a nurse hiking vaccines to a mountain village. Traditional ice packs melt; Thermavault’s salt solution stays cold for 10–12 hours and can be reused endlessly. Dr. Pritesh Vyas, who tested it, raved: “With a temperature monitor, it will be definitely helpful in remote places”. The teens are now building 200 units for hospitals and aiming for WHO certification to scale globally.
This isn’t just about cooling—it’s about equity. Over 1 billion people lack reliable electricity, and COVID-19 exposed how vital cold storage is for vaccines. Thermavault tackles climate change (no emissions!) and plastic waste (replacing single-use coolers) while saving lives. Plus, it’s a reminder that sometimes, the best solutions are hiding in plain sight—or a science textbook!
Want to geek out over the salty details? Dive into the full story of these teen innovators and their journey from classroom experiments to changing healthcare. Who knew salt could be this cool?
