How to: Sleep Warmer

Being cold at night is the worst.

We believe that laying down to sleep should be the coziest part of your day, not an 8 hour shiver-fest. There are so many factors that can influence how you feel in your sleep system. If you are taking your system to new lows or aren't as warm as you would like to be, troubleshoot your sleep system and try these tips for sleeping warmer.    

Troubleshoot Your Sleep System

1. Does Your Sleeping Bag Match Your Sleeping Pad?

Our sleeping bags are designed to be used with sleeping pads of similar thermal value. A zero degree bag with a non-Insulated pad is not going to keep you warm. Getting your body off the ground is crucial to maintaining warmth year-round. When your body comes into contact with cold ground, the ground acts like a vacuum, sucking the warmth out of you. Contact with cold ground will impact your body temperature more significantly than contact with cold air. Make sure your sleeping pad's R-Value matches the temperature rating of your sleeping bag (And your environment) and that they are the same size (I.E. a petite pad with a wide-long bag isn't ideal). 

Pro Tip: Big Agnes System Sleeping bags do not feature insulation on the bottom, so you'll need an appropriately insulated sleeping bag for a comfortable night's sleep.

2. What is the Degree Rating on Your Bag?

The temperature rating that a bag is given is based on the low end of the comfort spectrum. That degree rating is highly subjective and can be influence by a range of factors including your body fat, hydration level and style of tent you are using. In general, choose a bag that is rated for the coldest conditions you would use it for. Ventilating when you are too toasty is easy, adding warmth in the backcountry can be tricky.

Pro Tip: Men's and Women's sleeping bags are rated differently! Put simply, at the same advertised temperature rating, a Women's sleeping will be more insulated than a Men's. For the long story, check out our article on how to pick a sleeping bag.

3. What Size Is Your Bag?

Sleeping bags are not a one-size-fits-all, fancy Snuggie. For maximum warmth for your backcountry bed, choose a bag that contours to your body without being too tight. The heat trapped between your body and the bag is what keeps you warm at night. You need enough room to create that pocket of warm air. A bag that is too small will cause cold nights. If you have too much room, you won’t be able to efficiently heat that air pocket causing your body to expend more energy for less warmth. 

4. Is Your Sleeping Bag Clean?

Dirt, sweat and oil can cause your bag’s insulation to clump-creating cold spots and impacting your bag insulation's ability to loft. You can get your bag warm and fluffy by washing it after moderate use.

Sleep Smarter

Sleeping bags don’t make you warm, they keep you warm. They act as insulators by trapping your body’s heat. You can help your bag insulate you by stripping down to base layers before you get in.

Get down to your skivvies 

On a cold night, it can be tempting to hop in your bag with all your layers on, but this can lead to sweating eventually making you colder. It also prevents your body heat from warming the bag, ending up with a warm core, but cold hands and feet because your body heat is in your layers instead of the bag as a whole. ISO testing standards assume the sleeper will be wearing only base layers and a hat for optimal performance.

Choose Wool Base Layers

If you are a cold sleeper, try adding a pair of thick wool socks, gloves and a wool hat, paired with a thin wool base layer. Wool is exceptionally breathable and retains 70% of its warmth when wet (wet synthetics retain only 30% of their warming capacity and cotton has 0% warmth retention when wet).

Put a Hat On

A hat is your quickest fix. Up to 50% of your body heat is lost through your neck and head. If you can sleep in a hat you will be amazed by what a difference it makes. Do not burrow your head deep down in your sleeping bag, the moisture from your breath will wet your bag and make you even colder.

Before You Go To Bed

• Empty your bladder. Go before you get in your bag and don’t hold it until morning- your body will waste energy trying to keep urine warm. Sleep better and warmer by letting it go.
• Drink something hot- your body needs to be well hydrated to heat efficiently
• Eat something fatty (your body needs fuel to create heat, fats burn slower and help your body heat more efficiently)
• Do some sit-ups or jumping jacks to warm your body up. Your body heat is crucial for heating your bag up.
• Lay your bag out when you set up camp. Give it a couple hours to loft, so that down, foam and insulation are at maximum thermal capacity when you are ready to hit the hay.