WarmX undershirt

While heated garments may not be suitable for everyday wear, the WarmX undershirt would be useful for snowboarders, bikers, or ice truckers. The battery-powered shirt includes two warming zones located atop the kidneys (WarmX explains that blood is warmed as it runs through the kidneys). If the idea of heating up your kidneys scares you, you might want to check out Uniqlo's Heattech clothing. Its high-tech fabric converts sweat droplets to heat.