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Three out of every four people are side sleepers, yet for the longest time, the sleeping bag industry didn’t design with that in mind. Standard bags have less insulation on the bottom, where back sleepers typically compress the fill. So, when side sleepers roll over in these bags, they expose half their bodies to cold air. That was a chilly inconvenience until Big Agnes released its side-sleeper-focused line. Now, the Big Agnes Sidewinder SL 20°F, which earned our coveted Editors’ Choice Award in 2021, is on sale for over $60 off.
Let’s get into the design. It’s built for thermal efficiency, from the footbox shaped for feet on their side to the hood that’ll seal out drafts and keep a pillow in place when rolling around. The dimensions are also a tad wider than standard back-sleeper bags because side-sleepers tend to curl up into the fetal position.
“This bag felt like a sheath,” our 6’2” former executive editor said after testing this bag over some cold, 30°F November nights in Badlands National Park (he used the long size). “It moved with me as I rolled over to reduce pressure on my hips at night, but it never felt restrictive. I’m glad to not have to change my sleeping style to meet my equipment anymore.”
Not planning any trips to temps dipping below freezing anytime soon? The Big Agnes Sidewinder SL 35°F is on sale, too. The men’s bag is 40 percent off, and the women’s is 30 percent off.
From 2025