Cocoon Primaloft Overbag

The Cocoon Prima-loft Overbag is advertised as the perfect solution to add up to 20 degrees of warmth to your sleeping bag and at the same time provide excellent external moisture protection.   The Overbag itself is filled with 2 layers of Prima-loft insulation on each side and the top.  The bottom and the shell are manufactured of a nylon Rip-stop that repels moisture.  The bag also comes with a 1/2 length YKK zipper and a nylon compression style stuff sack for easy storage and transport.    The design of the Cocoon Prima-loft Overbag allows for an outdoor enthusiast to use the Overbag to add warmth and moisture protection to one’s sleeping bag and also use the Overbag as a lightweight summer bag.  This allows the Overbag to be used in a variety of travel and outdoor settings.   This Overbag comes in a black color and one size.

Field Report

Upon receipt of the Cocoon Prima-loft Overbag, I began an inspection of the bag. And immediately noticed that it seemed very light, yet the nylon rip stop outer shell seemed tough and durable.  The YKK 1/2 zipper seemed to function smoothly and without drag.  The 2 layers of Prima-loft insulation seemed “fluffy” and packed down tight and small into the provided nylon compression sack.  The small packed size would allow someone to store the Overbag with their sleeping bag inside the sleeping bag compartment of their backpack.  I decided to begin using the Overbag in the late winter and early spring while backpacking in the Ozark Mountains.  With overnight temperatures in the low 20’s and light snow, I decided to use my 30-degree sleeping bag with the Cocoon Overbag.

After storing the Overbag in my sleeping bag compartment, I removed the Overbag from the compression stuff sack and proceeded to put it over my sleeping bag.  My mummy style sleeping bag fit well inside the Overbag and the YKK zipper seemed compatible with my sleeping bag.  Upon getting inside the sleeping bag, the Overbag definitely seemed to add several degrees of warmth, along with providing an added degree of comfort.

While sleeping through the night, with temperatures in the high teens, the added warmth of the Cocoon Overbag made my 30-degree sleeping bag warm and comfortable.  I also noticed that upon waking, condensation had built up inside my tent and on top of the Overbag and due to the cold temperatures, the condensation had changed into frost and ice.  The Nylon rip stop prevented the inside of the Overbag from getting wet and the Primaloft insulation also seemed to perform well in areas of the Overbag that did get damp.  My sleeping bag itself showed no signs of moisture or dampness.

During the remainder of the late winter and early spring, I continued to use the Cocoon Overbag with my 30-degree sleeping bag, which essentially turned this 30-degree sleeping bag into a 10 or 15 degree bag.  I also continued to be impressed with the moisture protection that the Overbag provided for my down sleeping bag.

As the weather warmed into spring and early summer, I began using the Cocoon Overbag by itself as a light-weight summer sleeping bag.  The Overbag provided plenty of comfort and warmth as the weather began to warm and at the same time the Nylon rip stop shell and Primaloft insulation continued to provide protection against the moisture during the rain of spring and early summer.

I stored and cared for the Cocoon Primaloft Overbag as I would any other sleeping bag that I owned.  I stored the bag in a closet by hanging it from the wall or ceiling and cleaned the shell with a clean cloth and warm water.  This is generally all that is needed to clean the shell of the Overbag of dirt and debris, but the Overbag can be machine washed per the manufacturer’s instructions.  After several months of both winter and spring use, the Overbag showed little signs of wear and continued to perform as new.

The Cocoon Primaloft Overbag could be a welcome addition to most outdoor enthusiasts gear collection.  With the added temperature rating obtained from the Cocoon Overbag, you can turn a summer sleeping bag into a fall season sleeping bag and a fall season sleeping bag into a winter sleeping bag.  The Cocoon Overbag also provides added extra protection against moisture and the elements.

Gear Details

  • Manufacturer: Cocoon
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