In summer, if it is hot, I just sleep in my shorts. Usually I wear a tank top under my hiking shirt, so often I sleep in that also. That and the layer of clothing keeps my sleeping bag a lot cleaner inside. In winter, I many time sleep with my down jacket on, inside my bag, with hat, liner gloves and down socks on.

Backpackers prioritize sleepwear that is lightweight, multi-functional, and temperature-regulating, often following the "baselayer" philosophy. In 2026, the most popular choice is merino wool or high-tech synthetic blends. Merino is favored because it is naturally antimicrobial, meaning it won't smell even after several days of wear—a critical feature when you are carrying your entire life on your back and laundry facilities are scarce. In cold environments or high-altitude camps, backpackers wear "long john" style leggings and a long-sleeve top to maximize the warmth-to-weight ratio. In warmer tropical climates, "technical" silk or lightweight nylon shorts and a breathable tank top are standard. Many backpackers also opt for a dedicated pair of "clean" socks used only for sleeping to keep their feet warm and prevent the grit from their hiking boots from entering the sleeping bag. The ultimate goal for any backpacker's sleep system is "minimalism"; they want items that can serve as an extra layer of warmth under their hiking clothes during a chilly day while still being soft and comfortable enough to ensure a good night's rest in a tent or a hostel bunk.