Traditional bags leak heat
Why did the mummy sleeping bag get created in the first place? Traditional sleeping bags release heat from the bag out of the top by the head of the person trying to stay warm. The mummy sought to fix that problem by tightening the fit of the sleeping bag around the head to keep the heat from escaping. The mummy bag creates a nice seal to trap the head around the body to keep the person warm inside. But, to achieve the heat seal of the mummy bag, heat and mobility had to be sacrificed.
Mummy bags provide little room to move around in when you are sleeping
It happens just about every time. You set up camp, you enjoy a nice campfire dinner, chat with your friends until the temperature is too cold to stay and sleep is staring to overpower, you go into your tent, get ready for bed and slide into your sleeping bag, you cinch it up nice a tight to keep yourself warm, and then it happens; you have an itch on your back. You reach your opposite hand over the itching shoulder to try to scratch it, but the sleeping bag is too tight. You reach around the other side with your other hand only to find the same problem. You fidget and fidget only to finally give up and unzip your sleeping bag, release your arms from the trap and finally scratch that itch. The mummy bag design keeps you warm, but also keeps your moving severely restricted.
Kodiak Z-Top Sleeping Bag Design to the Rescue
Kodiak's sleeping bag design helps solve the problems with both sleeping bag designs. To help seal the warmth in the sleeping bag, the Z-Top cover allows you to put your head through the opening and lay it flat beneath your had, thus trapping the heat inside the bag. Your mobility in the bag is maintained by keeping the same, traditional rectangular shape for the rest of the bag all the way down to your toes. Your arms can freely move behind your head (underneath the Z-Top opening) and the rest of your body can get situated in just the right spot. Kodiak does just stop there though, the zipper trails are all covered and insulated to ensure no warmth is leaking through the zipper all the way down to your toes. There is nothing out there quite like a Kodiak sleeping bag.