When making use of any kind of resting bag all-time low of it is typically the most vital when keeping you warm on a cold night. When you lay down you have the tendency to squash the protecting material between you and the surface below triggering the insulation not to function quite possibly. In order to help with this trouble it is advised that you place a pad or non crushable protecting material below your bag. The zipper of a rectangular sleeping bag is constantly the week factor for losing heat nevertheless with today's modern technology the heat loss is typically minimal as compared to older designs.
The other sacrifice is the size or thickness of the bag. A mummy sleeping bag essentially will certainly be much smaller sized for bring around which is why it is a preference for many backpackers/hikers. The rectangular resting bag isn't as small yet because it's not common to be lugging it, apart from somewhere in a vehicle while getting to your intended location, the bulkiness of the bag is not as large a problem.
The ideal way to pick a cozy enough bag is to go with one that handles a 10 degree colder climate than exactly what you're anticipating to be resting in. The last most significant consideration in selecting a bag is the insulation that is made use of in that bag.