Professor Kripa Varanasi stepped out of a New Delhi airport in June 2024 expecting heat, but not the kind that kept him confined to his hotel for an entire conference. At 104 degrees Fahrenheit at midnight, with daytime peaks near 122 degrees, the air was suffocating—a far cry from his childhood in India. "When I grew up in India, it was not like this," Varanasi recalls. That experience sparked something in him: a determination to help tackle the escalating crisis that's silently killing the world's most vulnerable people.
Extreme heat is no longer a problem for tomorrow. It's a crisis claiming lives today, primarily among populations in the Global South who lack access to active cooling systems. As the planet warms and air conditioning demand accelerates, MIT researchers recognized an urgent need: to cool people, not spaces. That vision prompted the MIT Climate Project to launch the Critical Cooling initiative, a seed funding program designed to catalyze radical new approaches to heat management. Four teams of researchers received grants totaling $450,000 to develop proof-of-concept prototypes over six months—and all have shown genuine promise.
Varanasi's team developed a wearable personal cooling system that could protect individuals directly from lethal heat. Yet-Ming Chiang explored subsurface wells with heat-absorbing materials that could supply apartments and homes with dramatically cooler air while using far less energy than traditional heat pumps. Asegun Henry investigated an elegant alternative using cheap, abundant rubber—a "caloric" material—paired with plain water as a heat transfer fluid, eliminating the need for potent greenhouse gas refrigerants altogether. Gang Chen tackled the environmental cost of conventional air conditioning itself, designing refrigerants with zero greenhouse gas impact to replace today's highly damaging coolants.
The scale of the problem is staggering. Worldwide, only about 8 percent of people have access to air conditioning. Yet the existing systems already contribute between 3 and 4 percent of global warming emissions—a proportion that will explode as demand climbs. Chen projects that air conditioning markets will triple or quadruple in coming years, particularly in regions least equipped to handle the environmental fallout. These are the same regions where poverty is highest, power infrastructure is fragile, and heat fatalities are already mounting.
The initiative emerged from collaboration between MIT's Sustainable Design Lab and Harvard's Human Rights Entrepreneurs Clinic, reflecting a shift in how climate innovation addresses inequality. Led by Christoph Reinhart, the program brought together representatives from the World Bank, leaders across the Global South, and industry experts in a workshop designed to spark cross-pollination between research and real-world need. That's crucial: these aren't theoretical exercises. These prototypes are being designed explicitly for implementation in single-family homes, apartment buildings, and data centers where demand is most acute.
Progress has been tangible. Most teams produced working prototypes within their six-month window. Gang Chen, who already had ideas but lacked experimental resources, built three prototypes and tested them. "I'm not at the stage where I can say that I know this will work," he notes cautiously, yet the experimental results have convinced him to push forward with another iteration. If successful, he says it could transform air conditioning technology globally.
The MIT Climate Project and its partners are now exploring funding pathways to advance these concepts further. The message is clear: cooling innovation isn't a luxury for the future—it's a lifeline for today.