Prominent New Zealand Mountaineer and double amputee Mark Inglis says you need to know what you're doing to tackle Mt Cook.

There are currently considerable or high avalanche risks for many South Island mountains.

Five climbers were caught in an avalanche on Gammack range, east of Mount Cook yesterday.

One injured person was choppered to hospital with shoulder injuries... and everyone else was safe.

Mark Inglis told Simon and Phil the conditions are always treacherous this time of year, and those climbing need to be very experienced.

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