5 season sleeping bags are designed for use in cold and extreme conditions and are the warmest sleeping bags you'll find. Of course seasons can be different depending on your destination, so many people judge the performance of their sleeping bag by its comfort temperature. The comfort temperature provides a more of a universal indication of its warmth and suitability for your chosen activity and where you will be using the sleeping bag.
5 season sleeping bags (of 4+season sleeping bags) are perfect for expeditions and generally include features such as insulated baffles, durable water repellent shells and technical insulation that performs well in damp conditions to maintain its insulating properties.
I was looking for a bag for my daughter's upcoming trip to Nepal knowing that it would need to be warm and light. Having searched extensively I decided that the Chrysalis 4 fitted the bill. Although we have not been able to test it to its limits yet it has been very snug down to the -2C that we have used it so far. I had read a review that suggested it would require practice to get the bag back into the stuff sack but I found it much easier than suggested.
