We will be bold here and say it outright: for its weight, the Pyro is the warmest jacket you will find anywhere. The secret to its warmth lies not so much in the amount of down it contains, which is only 180 g of 850 cu.in. Polish goose down, but due to the fact that – uniquely for such a lightweight jacket – the Pyro features a box-wall baffle construction. This makes the Pyro considerably warmer than jackets with far more down but using stitch-through baffles that leak heat like a colander drains water.

The cut is generous in length and the adjustable hood design fits comfortably over most climbing helmets. The two hand-warmer pockets are complemented by an internal chest pocket.