In Hotwired, science editor Bill Gifford explores how heat can improve our performance and our health. Combining cutting-edge science, personal discovery and practical insights, Gifford reveals how humans evolved to excel in hot conditions and how we ve lost touch with this ancient advantage.

He plunges into the steamy world of Finnish saunas, serves as a test subject in heat labs and tackles a 100-mile bike ride under the blazing Texas sun to show how exposing ourselves to discomfort can expand our physical and mental limits. He even explores how infrared sauna therapy and cold plunging could fight depression more effectively than medication.

And he examines how, in cities around the globe, social saunas are reviving communal wellness.