Besides a backpack, there’s one specific item separating the long-term shoestring traveler from the vacationing tourist: a sleep sack. Sometimes called a sleep sheet or travel sheet, it’s a staple of travelers who won’t be finding 600-thread-count Egyptian cotton draping the next bed where they will spend the night. When the place you bed down costs less than the guests at the luxury hotel tip their bellman, you need a sheet of your own that will come between you and the mattress you can’t fully trust.
I’ve been checking out two just-introduced sleep sacks that are leaps and bounds beyond what I carried with me on three trips around the world, however, Modern technology has transformed the lowly travel sheet into something as comfortable as it is functional. Here’s the rundown on ones from Cocoon and Sea to Summit. Either one is a great choice. You get something lightweight and easy to carry that is also comfortable. The big bonus though? Both have built-in InsectShield protection, so you can doze off in a cheap guesthouse without first slathering yourself in DEET.
Lightweight and Compact
The Sea to Summit Coolmax Adaptor with InsectShield weighs in at 8.6 ounces (244 grams) and stuffs into a slightly smaller pouch than the Cocoon InsectShield Safari sheet, which is 10.8 ounces 
(305 grams). The Cocoon one has slightly thicker fabric, which isn’t necessarily a bad thing. Each stuffs into its own little sack. After stuffing, the sack is like a Nerf football without the tapered parts at the end. The Sea to Summit sack has a little carrying or hanging handle, while the Cocoon one is vented on one side to allow moisture to escape. Both have a cinch strap at the top.
Coolmax Fabric
The fabric of these sheets is 100% CoolMax, the wonder stuff that wicks away moisture and stays cool against your body. You can sink wash it and know it will dry in a few hours. It feels like your favorite t-shirt or nightgown, but it won’t get soaked with sweat and stay that way. My daughter liked the Cocoon one so much she curled up on the couch with it and then took it to bed to sleep in as well for several nights. A good sign.
InsectShield Treatment
You can find a lot of sleep sheets and sleeping bag liners with those first two attributes. The real kicker with these new models, however, is the introduction of InsectShield. That’s the permethrin-based repellent that’s built right into the fabric. No smell, no fumes, no effect on your skin. But you can wash the fabric at least 35 times without it losing its effectiveness. I’ve used ExOfficio clothing with this stuff in it and have significantly reduced the amount of DEET I had to apply. Sleeping in this product would give you an added layer of protection in areas with lots of mosquitoes. There’s even a little hoodie flap you can pull over your head.
This is great all-around for long-term travelers and those staying in hostels, but naturally you could use it for camping trips too, either as the only thing you’re sleeping in or as a sleeping bag liner for an additional layer.
See more on the Sea to Summit Adaptor page and the Cocoon USA website. The first company’s model is easier to find than the latter, but both seem to still be in roll-out mode at retail. Expect to pay somewhere between $45 and $55 for these InsectShield versions, a bit less for a straight Coolmax one.
Search for the Sea to Summit sleep sack or REI.com or RockCreek.com
Search Cocoon Coolmax prices online
#1 by Linda - June 25th, 2010 at 20:48
This is awesome! I wish I had been able to pack one of these last time I was in SE Asia. It would have helped in all the cheap guesthouses with holey mozzie nets.
#2 by Auriette - June 25th, 2010 at 20:57
I’ve stayed in some pretty scary cheap hotels over the years, and I wish I’d had one of these then. I won’t go anywhere questionable without one in the future!
#3 by TheInfamousJ - February 16th, 2011 at 14:39
I was never a fan of CoolMax fabric. I gave it a good, honest try but it just felt … wrong against bare skin. I prefer the Cocoon sleepsack in silk or cotton. I then treat them with insect repellent designed for clothing. Put the sack in a ziptop bag. Add insect repellent designed for clothing. Close bag. Shake. Let sit. And you have your own version of this sleep sack for probably the same cost, but that feels better against your skin.
#4 by Jarrod - April 14th, 2011 at 08:38
I agree a sleep sheet is vital when camping. I camp a lot in the UK and the soggy ground can make a diffenece when wanting a good nightes sleep. Teh insect shield is always a good addition.