10 Best Sleeping Bag Liners 2025 in the United States

The Sea to Summit Reactor Sleeping Bag Liner is designed to add warmth and hygiene to your sleeping bag, making it a solid choice for campers who want extra comfort in cold conditions. Its Thermolite fabric provides good insulation with hollow-core fibers that trap heat effectively, helping keep you warm even below minus 5 degrees Celsius. The liner’s mummy shape and drawcord footbox allow you to adjust warmth and fit around your feet, which is useful for temperature control during chilly nights.

Measuring 85 by 31.5 inches, it fits most adults comfortably without adding much bulk or weight (just under 16 ounces), making it easy to carry on trips. The material is treated with odor control technology, so it stays fresh longer and reduces the need for frequent washing. Fleece and Thermolite typically wash well but can require gentle handling to maintain insulation. While this liner boosts warmth, it is not a replacement for a heavy sleeping bag in extreme cold, and the drawstring closure may take a moment to get used to for a snug fit.

For people camping in cooler weather who want an easy-to-pack, effective liner that improves sleeping bag performance and hygiene, this is a practical option. Its lifetime guarantee from Sea to Summit adds confidence in its durability.

The Sea to Summit Reactor Sleeping Bag Liner in Extreme Standard size (85 x 31.5 inches) is designed to add significant warmth—up to 25°F—to your existing sleeping bag, making it a solid choice for winter campers or anyone facing cold conditions. It uses advanced Thermolite Pro fabric, which is lightweight yet insulated, thanks to hollow fibers that reflect body heat back to you. This material also stretches well, allowing good freedom of movement inside mummy-shaped sleeping bags.

The liner's drawcord footbox is a feature that lets you adjust ventilation or snugness at your feet and works seamlessly with certain Sea to Summit sleeping bags. Another practical plus is the HeiQ Fresh odor control treatment, helping the liner stay fresh even after multiple uses, which is advantageous when washing opportunities are limited. Weighing just 0.38 kg, it’s fairly light and compact for backpacking.

While it excels in warmth and hygiene, the price point is higher than simpler liners, and the fixed size may not fit everyone perfectly. Care instructions should be followed to maintain the performance and odor control of the technical fabrics. This liner provides a stretchy, warm, and odor-resistant option that works well in winter and fits mummy bags, with a higher price compared to basic models.

The Browint Silk Sleeping Bag Liner is crafted from 100% natural Mulberry silk, known for its smooth, soft feel that won't irritate sensitive skin. Its silk material helps keep you cool in warm weather, making it ideal for spring, summer, and early fall camping or travel. Measuring an extra-wide 87 by 43 inches, this liner offers more room than typical single liners, which is great if you like to move around while sleeping or are taller. Despite its size, it remains very lightweight at just 6.3 ounces, and it packs down small into a handy carry bag with a hook, making it easy to transport.

The liner includes reinforced gussets in key areas for durability and even has a pocket for a pillow, adding comfort to your outdoor or travel sleeping setup. Temperature-wise, this liner is best suited for environments around 46°C (about 115°F) and above, meaning it is designed for warmer seasons or as a clean, comfortable layer inside your sleeping bag or a hotel bed rather than cold weather protection. Care involves machine washing with cool water and gentle handling to maintain the silk’s quality, which might require more attention than synthetic liners.

If you want a natural, breathable, and lightweight liner that adds comfort and keeps your sleeping bag clean during warmer months or hotel stays, the Browint Silk Liner is a strong choice. Those needing insulation for colder conditions or preferring fuss-free maintenance may want to explore other options.