The Seeland Heat waistcoat is made from a lined, lightweight fabric with stretch membranes in the sides. Inside, it has a heat-reflecting lining that not only prevents heat loss but also enhances the effect of the waistcoat’s heating membranes. The high collar is lined with soft fleece. In the parts of the upper body most vulnerable to cold – between the back and lumbar region – there are heating membranes sewn in. Using the associated smartphone app, these heating membranes can be set to the desired temperature between 30C and 52C. The membranes can also be set to 38C, 46C or 52C using the push button on the chest, so you are not dependent on your smartphone.