In Montana, the water’s cold and the summer’s short. Which means there ain’t a whole lot of outdoor swimming going on, all things considered. Outside of the dog days in July and August, does the thought even cross one’s mind? And yet, swimming is a wonderful activity, as simple and natural as running, and we should all do it more. It’s good for our health, both physical and mental. And there’s a certain childlike joy and sense of rejuvenation that come from a good swim. Hence, Swim Wild & Free: A Practical Guide to Swimming Outdoors 365 Days a Year (Bloomsbury, $24), in which author Simon Griffiths outlines how, why, when, and where to swim outside, no matter where you live. The book is astoundingly comprehensive—over 200 pages of information on safety, gear (for cold and rough water), and technique, plus personal anecdotes from outdoor swimmers young and old, expert and inexperienced, fit and flabby. Because, as Griffiths makes abundantly clear, that’s the great thing about swimming: anyone can do it.