Damage only seem to start if you STOP in a spot for too long. We are testing this on a scenario to try and limit free movement, but right now, people just run out to do things and are not taking damage unless they stand still for about half a second. This allows to go anywhere and to stop - if you need to - by just dropping a 3x3 brick floor, then just start running again.

Is this basically the only way the code will work? I assume that you can't just make the damage happen all the time ON the terrain rather then ON the terrain AND not moving?

Sorry for the late response. That isn't how I remember it working, but either way, I'm not really interested in testing/updating this mod unfortunately. Feel free to make a pull request on GitHub or request joint ownership of the mod on this site.

I've just had a look at it. You get damaged any time that you are on the terrain but if you stop for >3 seconds then fire appears at your feet and does even more damage. I've increased the standard damage a bit to compensate, because generally health is free in factorio anyway.

Ah ok, Was not really a complaint on my part, was just trying to understand how it was meant to work, but thanks for reply.