Good news: Some cotton no longer kills. Like any good gear girl, I've avoided wearing cotton for outdoor activities—it's comfortable, but when it gets wet it tends to stay that way, and wet clothing chaffes, saps body heat, and can induce hypothermia, even in mild conditions. Hence the saying.
After years of scorn, though, cotton is slowly creeping its way back into the “performance baselayer” category. A few companies are experimenting with cotton blends that they say wick sweat from your skin and dry quickly, whcih is exactly what regular cotton can't do.
I had heard that performance cotton works best in hot weather, so to test that theory I took a pair of Polarmax's All-Year Gear 365 underwear on a soggy day of paddling in August. Polarmax says the anti-odor, anti-microbial, and moisture-wicking properties of the 365s mean you can wear them for an entire year without washing. My paddling experiment was even wetter than expected—I forgot my spray skirt—but the 365s remained comfortable all day, and afterward dried out after only five minutes on the clothesline. I’m not willing to test the company's all-year performance promise (there's no way I'm wearing the same undies for an entire year!), but I will say that the next day, the 365s dried almost as quickly on my body after a quick run as they did on the line the day before.
How did Polarmax get synthetic-like performance out of boring old cotton? The undies are made from a 94 percent cotton blend with two kinds of yarn: an untreated version that absorbs moisture, and a treated version that pulls it to the underwear's surface for evaporation. At $25, they're not cheap, but with Polarmax's manufacturing, warehousing, and shipping facilities all within a 15-mile radius, they've got a great carbon footprint. Plus, they're comfortable.
Another interesting choice is Outdoor Research’s Frescoe Tee ($38) which is 85 percent polypropylene and 15 percent "drirelease" cotton. The blend gives the shirt the performance benefits of a synthetic and the look and feel of cotton. In my experience, the Frescoe doesn't wick well enough for baselayer duty on a backcountry ski expedition or a similar high-intensity, cold-weather activity. But it's a solid pick for hanging out at the beach.