I took some video but only scrambled up most of the way. This is by far the most active volcano I've ever been on and if Hood or Rainier started acting like that, I would glissade down that minute, and then drive back to San Diego to boot. But this mountain was booming and shaking. And, there was lava coming out - as I soon realized, underneath the rocks I was standing on. Listen for the hiss when the water lands on the rocks:
In a rare moment of common sense, I turned around. That's actually how I ended up getting back down, by throwing water every couple steps so I could figure out which rocks weren't hot enough to fry eggs, and by extension where the lava was not. As you can imagine, it's a little concerning that tourists are flocking to this place now because, as the article says, "hundreds of people live in the nearby village so they must be safe". Nice heuristic! I bet Spirit Lake, Washington and Pompeii and Joya del Ceren probably felt safe too. Lightning is also a problem around volcanoes, even in Iceland, let alone in tropical Guatemala during rainy season.