A book about the author's journey from couch potatoe to mountain climber. The book is mainly a testimony from a student of the Wim Hof method, which is a breathing technique and cold terapy which boosts your imune system and brings about other health benefits. It is an interesting book, not only for the explanation of the method but also for the journey the author went through and the interactions with Wim Hof himself. A good read.