Dhruv Chaudhary

What they built

Co-invented Thermavault — a portable, electricity-free refrigerator that uses salt-based endothermic chemical reactions to keep medical supplies cool for up to 12 hours without a power outlet or battery. Inspired by witnessing the challenges of transporting COVID-19 vaccines to rural villages in tropical heat, Dhruv and his teammates tested over 150 salt combinations before finding the right formula. Thermavault is reusable (salts are recovered by boiling the water) and won the 2025 Earth Prize ($12,500). The team plans to manufacture 200 units and distribute them to 120 hospitals for real-world testing.

Verified track record

• Business Insider (Apr 2025) (source)
• Good News Network (source)
• Earth.Org Kids (confirms ages 16–17) (source)
• Scholastic Science World (source)