Columbia Sportswear Radiator 40 Semi-Rec

[instant heat]

It looks like a disco party on the inside, but when it comes to heating up quickly, this bag is all business. Thousands of tiny silver dots on the liner reflect your body heat, claims Columbia. And it’s no gimmick, report our testers. They heated up faster in this bag than any other, and the lining still breathed well enough to prevent clamminess.

After getting seriously chilled while pitching camp in blowing snow at 10:30 p.m. in Colorado’s Gore Range, one tester said she was toasty just a few minutes after hopping into the Moonstone. Though it’s not as lofty as competitors, the Moonstone’s Omni-Heat liner and 800-fill down worked well enough in tandem that multiple testers reported having to vent the bag in temps in the 20s to avoid overheating. However, the thinner loft showed its weakness when we pushed the bag near its 15°F rating in Boise National Forest.

One tester reports that the initial burst of warmth was not sustained throughout the night at such low temps. Minor gripe: The Moonstone is not heavy, but for the price, we still wish it was a bit lighter. $499; 2 lbs. 5 oz.; 15°F; columbia.comFABRIC 100% nylon.
FEATURES
• Omni-Heat™ thermal reflective lining
• Omni-Shield™ advanced repellency
• 45 degree comfort rating
• LH/RH zip together
• Trapezoid footbox
• Sleeping pad retention loops
• Reg. 1lb 9oz fill weight
• Thermic MX™ Insulation
• Long 1lbs 11oz fill weight
• 7″x15″ compression sack included