When you are out on the trail a sleeping bag is an essential piece of safety equipment in case you have to spend a night out. Sleeping bags come in all temperature ratings but whether they are 0C, -20C or -40C rating, they are all the same size and designed for people in a tent or cabin who are in their thermals. In an emergency situation, you can try to get inside while wearing all your clothing, but in most cases you won't be able to do up the zip or will break it while trying to do it up. So you are then faced with taking off your nice warm -40C parka in order to get into a cold sleeping bag and then repeat it in reverse when you get up.
The answer to this is the Mushing Bag. This extra wide bag will allow you to get inside it with all your winter clothing on and even slide down inside it for a sleep or eat some food. The zip is a heavy duty 9mm one which opens top down and bottom up, so you can open the bottom to put your boots on, change your socks etc without getting out of the bag. The hood has a wide drawcord gusset which can be closed to a small diameter to keep the heat in and the weather out. The base has an inbuilt foam mat for insulation and comfort (removable for washing) and there are even tie down loops to prevent the bag blowing away.
Packed size is important and we have designed the bag to pack into a convenient size. Fold in the two sides, clip them together and fold as required. The finished pack is 42cm/16.5" wide in order to fit inside many sled bags and can be placed in the bottom of your sled bag or kept in it's own sac.
· Ultra wide 120cm/47" shoulder width (even big sleeping bags are only 86cm/34" wide).
· Upper layer is insulated with 400gsm of Climashield insulation, lower with 200gsm.
· Integrated foam mat for insulation and comfort.
· Heavy duty two way zip for ease of use and durability.
· Drawcord gusset in the hood can be closed to keep the weather out and the heat in.
· 135gsm/4oz nylon base is waterproof and tough.
· Upper nylon microfibre is windproof but breathable.
· Retroreflective material to aid night visibility.
· Packs into a sled bag friendly size.
· Packed weight 3 Kg
US Military Rating Table for Sleeping Bags
Theoretical Clo values for comfortable sleep
Category Clo Range Equilibrium Temperature 0C
Mid Season 2.0 to 3.5 +18 to +7
Winter 3.6 to 6.9 +6 to -17
Arctic 7.0 to 10.0 -18 to -34
Category Clo Range 6 Hours Sleep Temperature 0C
Mid Season 2.0 to 3.5 +13 to -1
Winter 3.6 to 6.9 -2 to -33
Arctic 7.0 to 10.0 -34 to -62
Equilibrium temperatures are the range for “a good night’s sleep”, while the 6 hours sleep temperatures should enable the user to rest and recover ready for the next day. They are based upon a narrow mummy shaped sleeping bag so the larger size of the Mushing Bag will reduce the temperatures. However since the wearer will have all or some of their outer clothing on inside the bag, this will increase the temperatures. On balance, the figures in the table are probably a good estimate of Mushing Bag performance.
The Clo rating of the Mushing Bag with 2 layers of Climashield Insulation on the top and 1 layer on the bottom is approximately 9 for the top and 4.5 for the bottom. The foam insert in the center section of the base adds 1.4 Clo.
In summary, based upon experience gained with Thinsulate insulation, the Mushing Bag will provide at least an extra 200C of comfort. If the user is warm at -250C, then inside the Mushing Bag, they should be able to sleep for at least 6 hours down to -450C.