Leo looked at his rectangular bag. "Mine is shaped like a bed. Yours looks like a... sarcophagus."
"First," Sarah said, pointing to the '20°F' stitched on her bag, "you have to know your limits. This is a , meaning it keeps me safe down to 20 degrees, but I’m most comfortable around 30. You’re using a 'summer' bag in the middle of autumn. You always want a bag rated about 10 degrees lower than the coldest night you expect." 2. The Shape (Type) how to buy a sleeping bag for camping
"Exactly," she laughed. "This is a . Because it’s snug and has a hood, my body doesn't have to waste energy heating up empty air space. Rectangular bags are great for car camping or people who move their legs a lot, but for warmth and weight, the mummy is king." 3. The Filling (Technology) "What's inside it?" Leo asked, poking the soft fabric. Leo looked at his rectangular bag
"I'm freezing," Leo admitted. "How is that bag so warm? It looks like a giant marshmallow." sarcophagus
Leo shifted on the hard ground. "I just bought the bag. I didn't think I needed a mattress."
"This is —actual bird feathers," Sarah explained. "It’s super light and compresses into a tiny ball in my pack, which is why it costs more. Your bag is Synthetic . It’s heavier and bulkier, but if it gets wet, it’ll still keep you warm. Down loses its warmth if it gets soaked." 4. The Hidden Hero: The Sleeping Pad
Leo sighed, eyeing the frosty grass. "So, I need a mummy bag with a 20-degree rating and a real pad."