Unlike some pieces of winter gear, the Thermolite® Reactor Fleece Liner doesn’t go into hibernation in the summer. It works really well as a stand-alone sleeping bag in air temperatures down to around 50°F / 10°C. If you have warm base layers, you may even find it comfortable at temperatures lower than this. The only thing you need to be aware of is that moving air will pass through the fleece material easily; so you need to be inside a shelter or use a tarp or poncho to keep you away from drafts.

The great part about using a Thermolite® Reactor Fleece Liner in summer is that if you are sleeping out in sandy or dusty conditions (for instance on a paddle trip, or mountain biking in the desert), you can take the Reactor Fleece Liner home and just throw it in the washing machine: it is much easier to take care of than a down sleeping bag.

Warm, light, compact, versatile – oh, and really comfortable, too.

This one really does go to eleven.