Tired of wrapping yourself in blankets or fighting over the thermostat button to stay warm? Layers are key, but can be in the way if your working out. Polar Seal apparel by company Fillony is a base layer zip top made from polyester that brings heat on demand with the push of a button.

The heating happens in two zones build into the shirt, one at the upper back and one at the lower back. The heating zones can be activated separately or simultaneously. Each zone has 3 heating levels, 40° C (104° F), 45° C (113° F), and 50° C (122° F), which sounds pretty toasty. It only takes 10 seconds for the shirt to heat up, which means you’ll feel nice and warm pretty quick.

The heating elements are lightweight, flexible and breathable. In addition, they are water-resistant, which means you can wear the shirt in the rain, and even wash it!

To heat up, the shirt is compatible with standard USB power banks. Using a standard 10,000 mAh power bank, at a low heating level, the shirt keeps you warm for up to 8 hours.

The shirt is engineered to be use for sports and was tested in Alpine conditions. The buttons, located at the wrist, are shock- and water-proof. You also don’t have to remove your gloves to use the buttons, which means that your hands can stay warm as well. The buttons are made out of rubber and with built-in colour LEDs indicating temperature and activated zones.

The fabric is composed of 92% polyester and 8% elastane, making the garment warm, breathable, comfortable, and flexible.

Polar Seal shirts are available in a men’s and a woman’s cut, and in various colours.

Photos: Fillony