Do They Ride Barrels Down a River as That in the Hobit Novel?

In the culture series by n m. Banks, a look to windward, it's apparently mentioned that lava rafting is an extreme sport that citizens of the culture participate in on unfinished habitats. In fiction, molten lava only seems dangerous if you come into physical contact with it. So if you're just standing next to it or in close proximity to it, you're fine. Which, of course, would not be the case, because lava is extremely hot as well get into in this episode.