I confirmed my theory that I was basically killing myself :)
Bright Witch has a heat bar...something like this
|----------|-------|----------|
As she casts spells it heats up from the inside out.
|----------|-*****-|----------|
The middle of the bar is the safe zone. Once you pass the safe zone to you are overheating, we'll call it the danger zone.
|--------**|*******|**--------|
If you fill up the bar entirely, you explode.
You can vent the heat off which rapidly reduces your heat. This is where I misunderstood the mechanic.
I thought that once I was in the overheating zone I was taking damage so I always vented my excess heat when I got into the danger zone, and avoided going too high into the danger zone.
It turns out I had it backwards.
If you vent off heat while in the safe zone, everything is cool. *rimshot*
However, Venting off heat in the danger zone actually causes damage to yourself. It's a trade off for the ability to cast more spells without overheating. At it's core it's a health to mana spell.
If I let the heat cool off naturally, it is much slower but it causes no damage.
I can run the heat right up to the edge of explosion
|-********|*******|********-|
And I will take no damage from overheating. I can then switch to the sword to let it cool down naturally.
Before, every singe time I was peeking into the danger zone I vented and took damage.
Bottom line is now I can actually be a little more free with pouring on the damage when needed without taking a health hit unless I really decide it's worth the risk/reward.
Now we know...and knowing is half the battle...