Sea to Summit - Spark -18°C Down Sleeping Bag - Down sleeping bag tested

Warm, lightweight, and very packable! I tested it this winter during two mountaineering trips in Greece, at around 2000 m altitude with temperatures dropping to –11 °C (close to its comfort rating). It performed really well, keeping me warm and comfortable throughout the nights. Extra clothing beyond base layers was not needed, though I generally sleep warm. If your legs feel very cold at first, a Nalgene bottle filled with hot water works perfectly. Note: it was used in combination with a Nemo sleeping pad with a high R-Value — otherwise, the bag alone might not deliver the expected performance.

The discount available at the time also helped me decide on the purchase, and I really appreciate that it comes with a detailed report of the down fill quality. My only suggestion would be for the yellow, more water-resistant fabric to extend over a larger area for added protection.