Usually sleepingbags have a recommended lower sleeping- and maximum lower temprature. My bag have recommended temprature of -5 degrees & -10 maximum. I have always wondered if this was correct. This weekend I got a chance to test it. Stayed in a friends house this weekend. Was partying and we got really really drunk. Again. And it was a really cold night. Probarbly around -10 degrees. And because they have cats then I had really big problems with my breath and couldn’t sleep.So decided to test my sleeping bag. And it is true. My sleeping bag kept me warm.