I've joined, or at least sent a request to join the daily spitpaint group on Facebook. However, the group is open-content and so I was able to see the themes. The three options today were Sandworm, Lava Pit, and Sleeping Beauty.
So I decided to do a take on the lava pit and set the timer to 30 minutes.
Here's my result:
The painting doesn't exactly scream lava pit, but I'm still happy with how it turned out, even if I didn't manage to finish it in time. Hopefully it's clear what my interpretation is. For some reason the first thing that popped into my mind when I started was the idea of a lava vendor in some downtown slum to keep people warm. The idea is absurd but it was enough to go on. The perspective is a bit whack, and the scale of the characters don't really make any sense, but I'm happy with the warm and cold contrast, and the sense of scale from the smog in the foreground to the jet stream in the sky in the distance.