Which is a state of affairs I share with the sleeping bag industry. It's all rule of thumb "X" inches of dead air should result in "Y" insulation value, or dummy "C," when warmed and then cooled, should mimic human body type "D" and so on. The variables are endless: Individual metabolism, fat/muscle ratio, whether a person is tired or fresh, what they ate for dinner, and on and on.
Bottom line: For you, the Polarguard bag ain't cutting it. For someone else, it might be fine. Certainly, it sounds like you're doing all the right things. You have a good pad, you're dressing warmly (ignoring the old saw, "you'll sleep warmer if you go to bed nude!"), and wearing a hat to bed. It is true that eating a calorie-rich snack before bedtime can help; a Snickers bar or something like that can make a significant difference. Maybe keep a snack handythe metabolism of most people slows around 3 A.M. or so, which probably is why you're waking up cold around then.
Otherwise, you just need a warmer bag. Or maybe a silk liner ($40 to $60) would add just enough insulation to keep you comfy.
Our mission to inspire readers to get outside has never been more critical. In recent years, Outside Online has reported on groundbreaking research linking time in nature to improved mental and physical health, and we’ve kept you informed about the unprecedented threats to America’s public lands. Our rigorous coverage helps spark important debates about wellness and travel and adventure, and it provides readers an accessible gateway to new outdoor passions. Time outside is essential—and we can help you make the most of it. Making a financial contribution to Outside Online only takes a few minutes and will ensure we can continue supplying the trailblazing, informative journalism that readers like you depend on. We hope you’ll support us. Thank you.Contribute to Outside →