The drive to be outside, even in hot weather, is hard to overcome. People without air ­conditioning would be more likely to seek relief at their local park, ­according to Elie Bou-Zeid, a professor of civil and environmental ­engineering at Princeton, than at a government building where they can feel like climate refugees. “It’ll certainly be more pleasant to be in a park than in some indoor stadium where nobody wants to go,” he says. The scientists are combining inexpensive technologies, some novel, some already in use, that they plan to test first in New Jersey for deployment in hot spots like Phoenix.

Kirigami
The art of cutting and folding paper, kirigami is inspiring researchers to design structures that control wind in specific ways. A kirigami structure made from fabric and placed over misters could regulate wind speed to maximize cooling. Or it could form the roof of a pavilion, steering air into the structure.

Misters.Illustration: Michael Marczewski for Bloomberg Businessweek

Misters
They spray small ­water droplets that quickly evaporate, cooling the air. But the effectiveness of misters, which have long been used in cities such as Las Vegas and Phoenix, depends on wind speed. If there’s too little wind, the droplets won’t all evaporate; too much wind and the cooling effects dissipate.

Cold Tubes
This pavilion-like structure is built with panels that contain cold water pipes encased in a membrane that repels humidity. The panels (or “tubes”) draw in heat from the bodies of people standing outside the structure, making them feel cooler without actually cooling the surrounding air.

Sun Shades
Like shades seen at playgrounds, white fabric is stretched over parts of a small or midsize park to provide cover and reflect the sun.

Retro-reflective Panels
Researchers say it’s important to reflect heat from solar radiation away from people and surrounding structures. One solution is retro-reflective coatings that bounce sunlight back toward the sky. In an urban pocket park, retro-reflective wall panels could be attached to nearby buildings. In a larger park, the panels could be affixed to restrooms and other freestanding structures.