The book is a non fiction-based piece of popular science which unravels the amazing adaptive physiological responses that our bodies undergo as we push it to the limits in extreme sports and natural environments. Each chapter captures the history, geography and physical challenges which our bodies face when we as a species have tried to conquer the great outdoors. From Mt Everest to the South Pole, from a journey to Mars to the bottom of the Mariana trench, the book makes the subject accessible to readers, with a basic knowledge of science, and also tries to bring in the author’s own personal experiences and those of many legends from this sphere. For the reader (someone interested in science, particularly the life sciences or those who enjoy the outdoors and partake in extreme sports and outdoor activities), this is aimed to make physiology accessible and relatable, not as a piece of academic text. The reader will come away with a stronger understanding of human physiology (particularly at the extreme), how the body first deteriorates, then adapts and finally excels when faced with running a marathon, summiting Everest or going to Mars. Its cross functional nature, being a piece of non-fiction / popular science with personal anecdotes and history mixed in, will make for an interesting and memorable reading.