Mt Yasur in Vanuatu - the place to view a volcanic eruption

When you climb Mt Yasur, an active volcano on Tanna Island of Vanuatu, Oceania you can wear a helmet if you like. Will that protect you from falling rocks? Oh no, our guide told us with a grin, if a hot rock collides with your body you will instantly disintegrate. The helmets are for if you get scared and fall over when running from the volcano.