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Performance Enhancing Duds

A new fabric makes it cool to sweat

WHEN THE HUMAN BODY gets hot, it sweats to cool itself. In the past, apparel manufacturers have tried to help that process by developing fabrics that wick moisture away from the skin and expedite evaporation. A new technology, Omni-Freeze Zero, goes one step further, not only pulling moisture away from the body but also using it to create a cooling effect, according to Columbia Sportswear, the company that developed it.

Omni-Freeze Zero works by embedding a network of flat polymer circles in a light fabric. Up close, the circles are visible to the naked eye but not distinct enough to form a design element. As the circles get wet, they absorb moisture and swell into three-dimensional rings, an action that dissipates the heat energy, making the rings cooler than the surrounding fabric. How much it cools depends on many factors, including airflow, humidity, ambient temperature and moisture temperature. Still, when the wearer sweats, the garment's temperature drops and creates an actual cooling sensation.

Columbia has used Omni-Freeze in T-shirts, polos, jackets, hats and shoes, but it has not licensed the technology to other companies. That means the only way to get Omni-Freeze Zero is from the 76-year-old, Portland-based outdoors company. That may not sound hip, but it's cool.

[The following text appears within a diagram. Please see hardcopy or PDF for actual diagram.]

Transfer Point

As heat in the form of sweat (red arrow) enters the fabric, the polymer circles absorb the energy, creating a cooling effect.

Close Up

An image taken with a thermal camera indicates lower temperatures with darker blues and shows that the rings are cooler than the surrounding fabric.