Also, make sure you can function on sulfur dioxide, carbon monoxide, carbon dioxide and a fine assortment of other lethal gaseous elements possibly methane too from other climbers. This stuff can shut your system down....that is if you linger in the south bowl too long...be quick about it or take the West Crater Rim or the Wy'East if the snow is good and you know what you're doing...the vents are pumping out more gas now then in previous years.