I want to have an area while your in it you get hurt, exactly how to lava pools in transit were. But the main  deference I want is not to be set on fire, just for your player to be damaged. If any onw knows how to do this that would be awesome, thanks.

1. Place a trigger_hurt down where you want the player to be hurt

2. Tick the "slow" box (might be named something else but you'll see it)

3. give it the kvp dmg=amount of damage the player will take per second)

Example:
dmg=10 (kills player in 10 seconds if standing in trigger hurt)
dmg=100 will kill player instantly