This volcanologist has some serious stones

Now to say that this volcanologist is taking a big risk is an understatement.

Here are the facts:
This volcano is Nyiragongo in the Democratic Republic of the Congo, it has some of the fastest-moving lava flows ever recorded. The key feature of Nyiragongo is that lake of lava in the center of the crater that you see in the video. In January 1977, the lava lake was 2000 feet deep. When the volcano erupted later that month, the lake emptied dry in less than an hour. Lava was clocked at 40 mph.