When Paul Flaherty goes to work, he climbs into a four-engine WP-3D Orion turboprop plane and heads directly into the eye of a hurricane. Miles below, Hazel Barton's job in microbiology takes her to the depths of the world's most treacherous caves. And on the other side of the topsoil, way, way above the forest floor, Stephen Sillett passes his days (and sometimes his nights) in the canopies of the tallest trees on earth.

Welcome to the work--and worlds--of extreme scientists. From hurricanes to caves to the crowns of towering redwoods, these scientists battle some of the earth's most intense conditions in order to save lives, preserve species, and help us to better understand the way our planet works.