Scientists created refuges for the animals using painted masonry bricks inside greenhouses that they called “frog saunas”. They found that endangered Australian green and golden bell frogs were able to clear infections from the deadly Batrachochytrium dendrobatidis fungus, in the warmer conditions of the greenhouses, when they would otherwise have died. Many of the frogs that recovered in the refuges were then resistant to infection.

Doesn't sound like something that can just be dropped outside and the frogs use.