The Harkila Heat L/S T-shirt is a long sleeved T-shirt with built in heating membranes that can be set to exactly the temperature you desire. This makes it an excellent choice for a wide range of hunting and outdoor activities in the cold weather. The Harkila Heat L/S T-shirt is made from 80% nylon and 20% spandex, making it quick drying, stretchy and hardwearing. It has a modern cut, fitting relatively snugly to the body. In the parts of the upper body most vulnerable to cold – the chest, between the shoulder blades and in lumbar region – there are heating membranes sewn in which, using a smartphone app, can be set to exactly the desired temperature between 32C and 43C. The membranes can also be set to 32C, 38C or 43C using the push button on the chest, without using the app. The heating membranes are flexible enough to be folded up and packed away with the garment they are sewn into. The T shirt can also be safely machine washed. In a pocket on the right of the T shirt is a long, fabric covered cord with a waterproof USB plug, so you can connect a power bank of the desired capacity, which you can keep in your trouser pocket, for example. The pocket can be used to store the cord when the power bank is not connected. With a power bank of 10,000mAh, the T-shirt can output its highest temperature of 43C for about 7 hours at an outdoor temperature of 0C. To save energy, the heating membranes automatically go into standby once the jacket has reached the set temperature. They then turn back on automatically if the temperature falls 1-2 degrees below the set level. The result is that the T-shirt is heat regulating, because the heating function automatically turns off if you get hot from intense exertion and turns back on when you are sitting or standing still. The T-shirt is supplied with a drybag to pack it away in.

The Harkila HEAT User Guide can be downloaded here.

Main Fabric: 80% Nylon/20% Spandex, Single Jersey

Features:

• Crew neck
• Heat panel on lower chest, upper back and lower back
• Power button on chest for easy access
• Stow pocket for powerbank in right side seam
• Thumb holes
• Full stretch