The Adapt Interview Series #9: Tiffany Yeh (Eztia)

Extreme heat already affects more than 80% of the world's population. Each year it kills around 500,000 people and puts tens of millions of outdoor workers at risk. Air conditioning won't reach most of the people exposed, so what cools a construction worker on a building site or a first responder on the streets?

Tiffany Yeh has an unusual background for this problem. She trained as a materials scientist at MIT, then as a medical doctor at the University of Pennsylvania. She then spent a decade in international development, living in some of the hottest places on earth with little infrastructure and no air conditioning. That personal pain point led her to found Eztia, which makes cooling materials that protect people from heat using a fraction of the energy of conventional cooling.

Eztia's innovation, HydroVolt, is a gel printed directly onto garments. It pulls heat from the wearer's body and releases it through evaporative cooling. It recharges with water, either in the wash or by soaking the garment in a bucket, and then air dries.

The business is B2B worker safety. Eztia sells to employers such as construction firms and public safety agencies, and is betting on tighter worker safety regulations and a push for improved worker productivity to power sales going forwards.

Tiffany is candid about the technology's limits, but says founders should know exactly where they can win and double down on the niches where they can outcompete everyone else. She also challenges investors to back more deep tech, meaning products that require inventing and validating new materials rather than repackaging existing ones.