Sierra Designs' Backcountry Bed is a hybrid mixing mummy bag with down comforter/NPT

Evolution isn'™t unheard of when it comes to backpacking gear, and Sierra Designs and Therm-A-Rest have products that are proof of that when it comes to keeping you warm in your tent.

Sierra Design'™s Backcountry Bed

Sierra Designs continues to be a trend-setter with its Backcountry Bed, a three-season sleeping bag that'™s a cross between a mummy bag and a down comforter.

While mummy bags are great when it'™s cold, a key flaw in moderate weather is that you have to unzip to cool off. The result is one cool/cold side of your body, and one warm/hot side. Sierra Designs solves this problem with the Backcountry Bed.

While the basic mummy shape helps contain body heat, a panel on the top of the bag can be tossed back much as you would the covers of your bed. Fold the panel back, and you also have two insulated pockets to keep your hands warm. The design does away with the need for zippers, so no snagging in the middle of the night as you'™re trying to zip up or zip down to adjust to your comfort zone. There'™s a foot opening to poke your feet through if things get too hot down there as well.

These sleeping bags come with either 800- or 600-fill down, in either two-season or three-season models. Since men sleep a little warmer than women, the women'™s versions of these bags carry a bit more insulation (and a bit more price). A sleeve on the back of the bag holds your sleeping pad in place.

If that'™s not enough bang for the buck, Sierra Design stuffs these bags with its DriDown, so a wet bag will dry more quickly than other down bags. The 600-fill 3-season bag (MSRP $300 men'™s, $340 women'™s) is rated to 28/25 degrees, while the 800-fill 3-season bag (MSRP $400 men'™s, $440 women'™s) is rated to 31/25 degrees. You also can turn to 2-season Backcountry Beds, which are $50 cheaper.

Therm-A-Rest'™s Auriga Blanket

Though designed for sleeping, the Auriga Blanket makes a nice throw, too/NPT

There are times when you really don'™t need a sleeping bag. River trips in the middle of summer in Utah, for example, when the nighttime temps don'™t drop much past 65 degrees. That'™s when Therm-A-Rest'™s Auriga Blanket (MSRP $270 reg./$290 long) comes in extremely handy. It'™s an idea so obvious it should have come about long ago.

In essence, this is a blanket filled with 750-fill down that, when paired with a good insulating sleeping pad, will keep you warm down to about 35 degrees. The footbox is designed to slip over the end of your sleeping bag to hold things in place, while baffles run the length of the blanket to help keep out drafts. The blanket even has fasteners to attach to your pad if necessary.

While the shoulder and hip girth measurements are just 48 inches, keep in mind that this is a blanket and doesn'™t fully wrap you. There'™s plenty of room for movement. At just 1 pound, 8 ounces in the long (76 inches) version (fits to 6-foot-4), the Auriga Blanket is a great, lightweight sleeping alternative for summer backpacking trips.