What are PermaCool socks? PermaCool is our new range of cooling socks. We created the original Heat Holders range to keep people warm in winter. Now we've turned our attention to warmer weather, when many people have the opposite problem: feet that get uncomfortably hot and sweaty inside their shoes and socks. Like Heat Holders, PermaCool took over two years to develop. Now the technology is finally perfected, we're ready to bring it to the market. PermaCool socks are an ideal replacement for standard cotton socks in warm weather. They're designed for everyday wear, in both a regular style and a shorter trainer version. The range includes men's and ladies' sizes in a range of popular colours. How do PermaCool socks work? We usually think of cotton as the ideal fabric for hot weather. But in this case, natural isn't necessarily better. The human body naturally uses evaporation to cool itself. When we sweat, the moisture draws heat from our skin as it evaporates into the air, leaving us feeling cooler. The problem is that cotton socks soak up moisture like a sponge. (That's why towels are made of cotton.) The moisture blocks the pockets inside the fabric, preventing air from reaching the skin and locking in heat. As a result, people who regularly wear cotton socks and shoes can end up suffering from athlete's foot. However, PermaCool socks are different. They're made from a specially developed yarn with microscopic channelled fibres, combined with a unique knit and construction plus other specialised synthetic yarns. This unique design keeps air moving over the skin, whisking moisture away without absorbing it and keeping the feet cooler, drier and potentially healthier than regular cotton socks. In fact, we believe PermaCool are the driest, most comfortable cooling socks in the world. Putting PermaCool to the test PermaCool yarn has been sampled and analysed at a range of independent laboratories during its development, undergoing three main tests: Liquid Moisture Management (AATCC 195:2012): PermaCool achieves Grade 4, as compared to Grade 1 for a basic cotton sock in other words, PermaCool transports moisture four times as well. Air Permeability (BS EN ISO 9237:1995): PermaCool achieves 1221 m/s against 220 mm/s or basic cotton that's five times as much air passing through the sock. Low Absorption (SATRA TM47:2002): After four and a half hours, PermaCool has absorbed just 1.5 mg of moisture, versus 3.5mg for cotton socks. That means PermaCool retains just half of the moisture of regular socks, improving the fibre's ability to wick away moisture. The bottom line: compared to standard cotton socks, PermaCool allows five times as much air movement and is half as absorbent and four times drier.