How to Choose a Sleeping Bag for High-Altitude Trekking

A good sleeping bag is the difference between a restful night and a miserable one at altitude. Here’s how to choose.

Temperature Ratings Explained

Sleeping bag temperature ratings follow the EN (European Norm) standard. The “comfort” rating is for women, the “limit” rating is for men, and the “extreme” rating is the survival temperature. Always choose a bag rated 5-10°C colder than the coldest temperature you expect to encounter.

For Everest Base Camp (Gorak Shep can hit -15°C at night), choose a -20°C bag. For Annapurna Base Camp (ABC), a -10°C bag is sufficient. For Poon Hill, a 0°C bag is fine.

Down vs Synthetic

Down offers the best warmth-to-weight ratio and packs smaller. It loses insulation when wet, but high-quality down is treated (water-repellent) to resist moisture. Choose down for any trek above 3000m.

Synthetic retains warmth when wet and is cheaper, but it’s bulkier and heavier. Choose synthetic for lower-altitude monsoon treks where rain is constant.

Fill Power

Fill power (FP) measures down loft — higher is warmer for the same weight. 600 FP is basic, 800 FP is premium, 900 FP is expedition-grade. For most Nepal treks, 700-800 FP is ideal.

Shape

Mummy bags are warmer (less air to heat) and lighter. Rectangular bags are roomier but colder. Always choose mummy for high altitude.

Our Top Picks

• -15°C Down Bag — best for EBC, Manaslu, Kanchenjunga
• 0°C Synthetic Bag — best for Langtang, Poon Hill, Mardi Himal
• -25°C Expedition Bag — for winter treks and 6000m peaks

Pro Tips

Always use a liner — it adds 5°C of warmth and keeps the bag clean. Ventilate the bag every morning to release moisture. Store the bag loose (not compressed) between treks.