It is an active volcano and the last eruption was in 2010 - the first in 1883 - and the eruption is still described as "on going." Which provides me an excuse for postponing my climb. The temperature of its lava is said to be only 520 degrees Centigrade. I interpret this to mean there are for more hotter volcanoes on this planet.
Some of the information in this post accessed from http://en.wikipedia.org/wiki/Ol_Doinyo_Lengai.