Sea to Summit Spark Sleeping Bag

The 15-degree rating is a comfort-focused limit, but keep in mind that individual warmth varies significantly based on your sleeping pad, clothing layers, and metabolism. For true alpine conditions, we recommend pairing this bag with an insulated sleeping pad that has a high R-value to prevent heat loss through the ground.

The Spark features a technical mummy cut designed to maximize thermal efficiency by minimizing dead air space. While it is streamlined to keep you warm, it is more restrictive than a rectangular bag, so if you are a restless sleeper who tosses and turns, you may find the fit snug.

The non-PFC DWR treatment on the shell and hood is designed to manage condensation and light moisture, not heavy rain or soaking conditions. It is excellent for alpine environments where dew or frost is common, but you should always use a waterproof stuff sack to keep the down dry inside your pack.

Yes, the bag is designed for users up to 73 inches, or 6 feet 1 inch. If you are right at that height limit, you will have a close fit, so consider if you prefer a little extra room for layering or if you prioritize the weight savings of a tighter fit.

The 10D nylon is chosen specifically for its ultralight weight and packability, which means it is thin and requires careful handling. It is durable enough for standard backcountry use, but you should be mindful of sharp objects like zippers, buckles, or rough tent floors to avoid snags.