🧣 Which Fabric Will Keep You From Freezing to Death
13 materials compared on their dry and wet insulating power, drying time, and fire risk — backed by hard numbers to help you understand why "cotton kills".
★ When wet, cotton retains only about 10% of its dry insulating power, compared to 80% for wool — that's the exact metric behind "cotton kills".
★ Water strips down of up to 85% of its insulation AND takes over a day to dry: the worst combo in wet weather despite its excellent dry clo (0.55).
★ Merino wool insulates almost as well as down (0.30 vs. 0.55 clo) for a third of its drying time.
★ Jeans isolate as much in terms of clo as a waxed cotton windbreaker — but take ten times longer to dry (10 h vs. 1 h for a fleece).
Insulation (clo) : 1 clo = comfort sitting at 21°C; value for a standard layer of this material — higher is better.