Glossary - H

Heliolite Fabric is ultralight and downproof (low air permeability, which prevents down and feathers from leaking out from the inside of the sleeping bag). It provides an exceptional strength-to-weight ratio and is lighter and more compressible than many other available fabrics - Heliolite fabric is available in some of The North Face's down sleeping bags.

Berghaus exclusive Helium face fabric developed to Berghaus specification in conjunction with WL Gore and Perseverance Mills. This remarkable fabric uses high tenacity tightly woven nylon yarns to give an exceptional strength to weight ratio. The Helium face is laminated to the new Paclite III membrane to give a unique featherweight fabric which is over 50-100% more breathable than comparable lightweight waterproof fabrics currently available.

When you are cold waist, hem and collar drawcords can be tightened to trap heat within the jacket or trousers. Loosening the drawcords allows more ventilation when you are hot. Concealed toggles and cords will not flap in the wind or tangle around harnesses.

A tent designed to promote high to low circulation can travel from hot climates to cold far easier. This is due to a system of mesh panels and doors.

H.O.T. (Heatshield Optical Technology) insulation is built with 100% polyester hollow-core fibers. H.O.T. sleeping bags provides powerful thermal efficiency, and because the fibers are of variable thickness, they compress easily, without breaking down, resulting in a sleeping bag that's convenient to pack, yet doesn't lose its softness, warmth, or high volume loft.

The finest, premier leather at 3.0mm + thickness. Reversed Anfibio offers maximum strength, support and abrasion resistance. There leathers are "reversed" (i.e. with the textured side out and the tanned surface inside). This protects the hide's best surface from scuffing and abrasion, which improves durability and water resistance. Reversed Anfibio is a prime quality leather and should not be confused with ordinary leathers or suede.

All Scarpa Reversed Anfibio leather has the specialised HS12 tanning treatment which impregnates silicone into the leather, making the leather more water resistant. This treatment is durable and resistant to scuffing, stops the leather from wetting out so easily and dries out faster than traditionally tanned walking boot leathers.

A special tanning treatment used on walking and rambling boots, making the leather more water resistant, breathable and quicker drying than normal untreated leather. This treatment is durable and resistant to scuffing. All Sherpa, Nubuck and Reversed Anfibio leathers in the Scarpa boot range are given this additional treatment.

The all-in-one hub and swivel tent pole design used by some MSR tents are designed to be quick, strong and easy to use, whilst also being versatile in their use by creating 2 vestibules for dry entry and cooking, along with a living/sleeping area.

Hydration systems (or bladders) consist of a drinking tube and a bladder. The bladder does not need to be removed from your rucksack when you need a drink, simply suck on the drinking tube! Hydration systems help keep you properly hydrated and at your top performance. Decide how much fluid you need, how much storage you want, what style works, and chose your pack here. Hydration systems are now considered in many rucsack designs and can also be bought separately.

Hydro/dry performance fabric is exclusive to Sprayway. With its stable body microclimate and a waterproof rating of at least 5000mm Hydrostatic Head, it makes an exceptionally waterproof fabric for all-year round walkers. It has also offers excellent levels of breathability. It is often used in Sprayway Hydro/dry Jackets.

Durable performance fabric exclusive to Sprayway. Provides a stable microclimate for your body, and with a waterproof rating of at least 15,000mm Hydrostatic Head. Hydro/dry also offers excellent breathability and is also suitable for all serious trekking and walking enthusiasts. It is often used in Sprayway Hydro/dry Jackets.

A stretch Hydro/dry fabric providing added comfort for freedom of movement during your outdoor activity. Hydro/dry performance fabric is exclusive to Sprayway. With its stable body microclimate and a waterproof rating of at least 5000mm Hydrostatic Head, it makes an exceptionally waterproof fabric for all-year round walkers. It has also offers excellent levels of breathability for a variety of outdoor activities.

A stretch knitted outer finished with a durable water resistant (DWR) treatment is bonded to hydro/dry breathable membrane and thermal inner fabric to keep you comfortable on your walk in damp conditions.

There are many different types of waterproof fabrics for outdoor clothing and even more manufacturers of outdoor waterproof clothing of which hare tested for their waterproof-ness. The hydrostatic head is a property of the fabric that measures its waterproof qualities using the height of the water that can rest on the fabric before it seeps through.

So a fabric with a hydrostatic head rating of 1000mm will cope under the pressure of at least one meter of water - this is the equivalent to rain in 35mph winds, and is the minimum requirement for a fabric to be called waterproof in the UK. Tests are done along the seam as this is usually the weakest point of the item of outdoor clothing.

You can maintain the waterproofing of your tent by using a tent waterproofer - adding a water-repellent coating to polyurethane and neoprene-backed nylon, polyester and dacron fabric.

HyVent is a breathable waterproof polyurethane-based membrane designed to give complete weather protection. It is a well regarded breathable and waterproof outer layer with additional comfort and breathability via The North Face's 2 and 3 layer versions of the HyVent technology. Examples can be seen of the The North Face HyVent Jackets in the waterproof jackets and trousers section.