They can be deadly and strike at any moment, but how easy is it to spot the potential risks of an avalanche?
An Otago Polytechnic course designed to help students identify those risks is underway this winter, with a familiar face amongst those enrolled.
Course enrollee, and Olympic free skier Jossi Wells, will be the first to admit his knowledge of avalanches is limited.
"Before this course, my avalanche knowledge was don't get caught in one, cause you can die," Wells told 1 NEWS.
The 12 week course entails 10 weeks of online study before hitting the mountain at Treble Cone for a week's practical work.
The students will be tested this week, hoping to receive a certificate in Avalanche Risk Management.