Available on Amazon.com - Sun Company Brrr-ometer - Snowsport Zipperpull Thermometer | Skiing & Snowboarding Thermometer for Jacket, Parka, or Pack The Brrr-ometer can attach to a jacket, sleeping bag, backpack, etc. and is a convenient way to check the temperature. It's accurate and the build quality is nice. I checked it side-by-side with other