Therm-a-rest Polar Ranger Sleeping Bag review in a nutshell: If you need a sleeping bag that can keep you warm no matter the temperature outside, you'll need the Polar Ranger. Made from recycled and responsibly-sourced materials, Therm-a-rest's four-season sleeping bag is the ultimate cold-weather accessory for adventurers.
It's not often that I get to test four-seasons sleeping bags for our best sleeping bag guide in actual sub-zero conditions, but this is precisely what happened when I took Therm-a-rest's Polar Ranger on a trip to Mongolia. That adventure provided the perfect opportunity for me to test the capabilities of the Polar Ranger; one night, we even got to sleep on the ice.
