Black Diamond

Belay Parka £220

+ Extremely warm, moisture-resistant synthetic fill, great hood

- Bulky packed size, hefty weight

This classic belay jacket takes a simple approach to warmth: pack a ripstop shell chock-full of sheet insulation. Thick 200gsm Thermolite fill makes this one of the cosiest synthetic jackets around. It’s pretty much like wearing a sleeping bag, so you shouldn’t be cold even in sub-zero temps.

As an overlayering piece, the fit is generous, so you might want to size down. Note that the same fill weight is packed into the body, arms and hood too – there’s no body-mapping here, which doesn’t make for a svelte silhouette, nor, if we’re honest, optimum mobility. Then again, it’s designed for static use, and in that capacity it excels whether you’re hunkered down in a summit shelter or belaying a climbing partner in a windswept gully.

It’s worth highlighting the hood too, which can make or break an insulated jacket. This one is brilliant. It works with or without a climbing helmet and is exceptionally warm. Adjustment is via a single rear drawcord, but this simultaneously reduces the hood volume and pulls it in around the face too. We also liked the fleecy hand pockets, the useful two-way main zipper and the large inner dump pockets.

Downsides? Inevitably, weight and bulk. This one’s gonna fill the bottom of a rucksack, even if you’re toting a big winter pack.

■ Insulation Thermolite HL Eco-Made Synthetic Insulation (200gsm)

■ Shell 50D ripstop polyester 80gsm with PFC-free DWR

■ Sizes: Men’s S-XL Women’s XS-XL

■ Weight 845g (men’s M) / 718g (women’s M)