Have you ever heard someone use the phrase “4-season sleeping bag?” It’s a farce. 4-season sleeping bags don’t really exist, because a bag that’s warm enough for winter (say, a 0-degree bag) is likely to roast you in the summer sun.
4-season sleeping pads, however, are a different story entirely. A 4-season pad insulates you in the winter, but it won’t lead to overheating in the summer—so long as your sleeping bag is primed for the weather at hand, of course.
A common misconception is that, when it comes to keeping warm, the sleeping bag is more important than the pad. The truth is, it’s the cold ground that sucks the warmth right out of you, and so a true 4-season pad with ample insulation is essential in inclement weather.
Images by Drew Zieff
Insulation is measured by the “R-value,” which is essentially the “capacity to resist heat flow.” This number ranges from 1.0 to 9.5, with ultralight, minimalist backpacking pads on the lower end, insulated winter pads in the middle of the pack and thick, luxurious monsters on the higher end.
For example, on the low end, you have something like the Thermarest NeoAir Venture WV. For a reasonable price ($70 for a regular), the 2-inch-thick, 1 lbs 6 oz Venture WV has an R-Value of 1.8—meaning it’s not going to keep you very warm if temperatures drop below freezing. While a solid affordable pick for 3-season backpackers, 4-season enthusiasts should look elsewhere.
On the other end of the spectrum, there’s the Exped MegaMat 10. At 5.5 lbs, you’re not taking this behemoth backpacking, but if you’re constantly car camping in subpar weather, this is 9.5 R-Value pad is going to keep you warm and comfortable.
We recently tested the Thermarest NeoAir 4-Season pad, which has a high mid-range R-Value of 5.7, and we consider it to be the best sleeping pad in its class.
Oftentimes, people will layer an inflatable pad on top of a foam pad when winter camping. That’s far from necessary with the NeoAir XTherm Max, as we relied on this pad for multiple nights in Utah’s Wasatch Range. Temperatures dipped below zero, but all three of our XTherm Max testers stayed warm throughout the night in 0-degree bags.
At an ounce over a pound, the NeoAir XTherm Max is a champion in its weight class. Heat loss is reduced thanks to two complementary technologies: ThermaCapture, a reflective fabric that bounces heat back to the body before it even reaches the ground, and the Triangular Core Matrix which compartmentalizes construction into triangular baffles to stop heat from escaping.
Keep in mind: this isn’t just a winter pad. We’ve also comfortably slept on the XTherm Max with a 45-degree bag in summer weather. At 2.5 inches thick, it’s quite comfy—our only qualm with the pad is that the lightweight fabrics used are crinkly to the point where you might wake up your tent mates if you tend to toss and turn.
Considering the light weight, year-round versatility and class-leading technologies, our Active Junky gear testers agree that if you are only going to buy one sleeping pad, the NeoAir XTherm Max is the best you can get.