Something that caught my eye on a recent trip to Abruzzo, Italy (apart from the stunning location, great hospitality and wonderful weather) was the Therm-a-Rest Altair sleeping bag. It’s a four-season bag designed to be used in conjunction with their sleeping mats as part of a ‘sleep system’, thereby cutting down on weight and bulk and making for a more comfortable night under the stars. We particularly liked the neck baffle (snug but not constrictive) and the two elasticated straps to keep you from falling off the mat in the middle of the night. The lower strap is located high enough that is doesn’t restrict leg movement at all. It also has the rather brilliant addition of a small external pocket near the shoulder, for a watch, headtorch or other easily mislaid essential.
So, top marks for design. But what of the all important temperature/weight ratio? This is a pretty subjective area, but that 750+ goose down is rated for a Europe comfort rating of –5 (women), when it’s used with a winter mat rated to R4.7. The underside of the bag has less down in it, the logic being that down is only warm when it contains air, and any squashed (underneath the sleeper) is therefore much less efficient. Instead, there’s more on top, where it counts. The weight is 1120gms and it packs down small enough.
On my two nights in the bag, I found it very comfortable indeed, and the 30d nylon ripstop surface material with DWR should prove very durable and condensation resistant. Is this a true four-season bag for UK conditions? With the right mat and if you sleep warm, it could be. It’s certainly a well designed and built three-season option, with the ability to bulk up with additional down clothing should you need to. I’ll be testing this more on some cold, rainy weekends soon – well, it is Britain, after all.