People who sleep on their sides tend to have a rough time of it when they go camping. Unlike back or front-sleepers (yeah, apparently the latter do exist), the shape of the slumbering human body doesn’t conform easily to the hard, flat ground. Aching shoulders and hips are a common result. And that’s before we get on to the problem with standard sleeping bags, which tend to end up twisted around you like a boa constrictor, with the zip digging in uncomfortably somewhere underneath you. If that sounds familiar, the patent pending Sidewinder is going to be a genuine game-changer.