Scotland, Norway or the foothills of the Alps-for trekking in areas where the weather is changeable, a moisture-insensitive, lightweight sleeping bag is your best bet. A bag like the Airflake 0 Sleeping Bag Large from Jack Wolfskin. Incorporating the innovative synthetic fibre fill technology, it is guaranteed to keep you warm in all weathers, from spring right through to autumn. The special synthetic fibre fill is immune to moisture and ultra-lightweight. So you get maximum warmth at a minimum weight. The outer fabric is soft and wicks moisture effectively, so you get a pleasant internal microclimate-and a good night's sleep. And when you wake refreshed in the morning, the bag stuffs neatly into its waterproof pack bag.