At a park near Canberra, Australia, a series of small white pyramid-shaped boxes are part of a new experiment: Can “frog saunas” help bring back an endangered species?

The green and golden bell frog—an iconic Australian amphibian with a call that sounds like a cross between a power tool and a quacking duck—is already extinct in the area. Like other frog species around the world, it was a victim of a deadly fungus called chytrid that has been killing amphibians for decades. But scientists are reintroducing the vibrant frog with the hope that a design intervention can help it survive.

[Photo: courtesy Simon Clulow/University of Canberra]

The “sauna” is a simple design, with bricks inside a plastic enclosure that heats up in the sun. The bell frog loves sitting in the heat—and conveniently the high temperatures kill the fungus.

“The technology we’re using is extremely low tech,” said Simon Clulow, a conservation ecology professor at the University of Canberra leading the research.…