What are the rules for taking damage?
In my current game I am trying to get to oil by mining out spots to put big electric poles at their max range with a little space around them to lay radar.
But I am being damaged even when standing in the cleared area.
Do I have to connect the cleared area to my main base?

Once you pass a certain radius, if you're standing on ore and there's a certain amount of ore around you, you take damage. This check increases in area and the damage increases for each successive check.

It's a pretty wonky calculation and it's not really intended for single player.