Unfortunately LCD, normally a paragon of good answering, misread your question. ;D
Make a trigger:-
Activation box: anybody present Repeatable
Condition: this and var1
On activation: "_x setdammage (getdammage _x + 0.1)" foreach thislist
Use a looping script to switch the var1 from true to false as you like.
Syntax, and indeed the whole result, not guaranteed but its worth a try.
mac 2 : LCD 2