Having been a ski instructor in Alpe d'Huez for four seasons, I've spent a fair amount of my professional and free time off piste. As you're outside of the controlled area, if you do get in trouble, your rescue isn't guaranteed, which is why no mountain guide will take anyone in their group off piste without these three absolute essentials...

#1: Transceiver - The transceiver (often referred to as ‘beepers’) is an always-emitting ‘beacon’ that can be followed by any other transceiver to locate you under the snow in the event of an avalanche.
You wear it on your person, not in your bag(!), under the top layer of your clothes. Although new technology has made tranceivers very user-friendly, it’s paramount that everyone in your group knows how to use them, and practices regularly.   

#2 : Snow probe - After locating a person caught in an avalanche with the transceiver, use your snow probe (a long, thin collapsible stick) to help you pinpoint their exact location by pushing the stick into the snow. This is essential before you waste valuable energy digging them out.   

#3: Shovel - Once the person has been properly located, it’s down to the entire group to kick into action and get digging – time is of the essence. 

#4: Water - Dehydration sneaks up on you in the mountains. With the cold mixing with adrenaline and fatigue. it’s easy to forget to put essential water back into your body.

#5: Snacks - Think of things that won’t freeze. Flapjacks and chocolate will go rock hard in the cold. Gummy sweets, gels or nuts stay edible. When you’re almost out of energy at the end of the day, the extra sugar kick is often enough to get you home - or to the nearest bar!

#6: Sunscreen - Regardless of skill, the sun’s rays will still burn noses and cheeks even through the clouds, so this is an essential whatever level you’re at.

#7: First-aid kit - Hopefully you won't need it, but it’s a sensible companion to have with you.

#8: Compass and map - Once you’re properly trained, the mountains become a vast playground – where you can explore not just the areas marked out for the majority of skiers and boarders, but also into neighbouring valleys and away from the beaten tracks.

#9: Multi-tool - Things often need tightening, adjusting or fiddling with. Every lift station will have them but it’s a good idea to carry a small one as you probably won’t be near a lift.

#10: Neck warmer - As with other spare layers, keeping all exposed skin covered and dry from the elements is essential if, or when the weather turns.

#11: Spare inner gloves - There’s nothing worse than cold, wet hands when you’re trying to enjoy the mountain.

#12: Spare hat - You never know what might happen - mountain weather changes and suddenly you need the extra layer, or maybe an unexpected tumble leaves the one you’re wearing wet and cold from the snow, or lost!

#13: Spare thermals - A spare thermal top for personal use, or to help out anyone else who gets cold.

#14: Hand warmers - Hand warmers keep fingers toasty on the lifts, in lift queues or any other time you’re hanging about. 

#15: Foil blanket - Just in case you get stuck out for longer than you anticipate. It’s better to have it and not need it.

#16: Spare eye wear - Despite the best intentions, goggles can mist up and it’s tricky to de-mist them.

#17: Cash - You never know, maybe your free-ride day spins you off course and you end up needing a taxi back from a neighbouring village!

#18: Touring skins - These are used on the bottom of special off-piste skis to grip the snow and allow you to walk up the mountain. These skis also have special bindings which allow you to lift your heels and walk to more remote areas of the mountain, or out of places you might have skied into!

#19: Touring crampons - Not always essential but on some steep or icy ascents, the touring skins simply don’t give enough grip. Metal crampons - similar to those that ice climbers would use - attach to the bindings for extra assistance.

#20: Duct tape - You never know what might happen up a mountain; tears to clothing, bags, goggle straps, gloves - anything! If you can’t fix it with duct tape - you haven’t used enough.

#21: Camera - A GoPro with a couple of attachments. No longer can your heroism be exaggerated; watch back your day’s events and brag with evidence.

Take these essentials with you and you'll be prepared for most eventualities. Just don't forget THE most essential item of all, your own common sense!