Three teenagers from Indore, India—Dhruv Chaudhary, Mithran Ladhania, and Mridul Jain—have developed a groundbreaking refrigerator that operates without electricity, using only salt and water. Their invention, named Thermavault, aims to preserve vaccines and medical supplies in remote areas lacking reliable power sources.

The inspiration came from their families' experiences in the medical field, highlighting the challenges of transporting COVID-19 vaccines to rural regions. Thermavault employs a chemical reaction where specific salts, upon dissolving in water, absorb heat from their surroundings, effectively cooling the interior. This passive cooling method can maintain temperatures suitable for vaccine storage for up to 12 hours.

Their innovative approach earned them the 2025 Earth Prize, along with $12,500 in funding. They plan to produce 200 units for testing across 120 hospitals, potentially revolutionizing cold-chain logistics in underserved areas.

Thermavault not only addresses a critical healthcare need but also exemplifies sustainable innovation. By eliminating the dependence on electricity and harmful refrigerants, it offers an eco-friendly solution to a global challenge.

In a world seeking sustainable and accessible healthcare solutions, Thermavault stands out as a beacon of hope.