Thermal Shockwave: Power: Absolute Zero deals up to 3 targets 1 cold damage each. Absolute Zero deals himself X fire damage where X = the total amount of cold damage dealt by Absolute Zero this turn.
I’ve never noticed this before, but the part of Thermal Shockwave that deals damage to AZ based on the amount of cold damage dealt by AZ doesn’t seem to limit that amount to damage done via the Thermal Shockwave card itself. In other words, if I’m reading this right, damage that AZ had done previously in the turn (say, via Impale, Cold Snap, or a one-shot like Hoarfire) would also count. Is that right?
If so, Thermal Shockwave might sometimes be hard to use, as an AZ with both modules and Focused Apertures could easily be doing quite a lot of cold damage via Cold Snap, etc. such that AZ wouldn’t have the hit points to take all of that fire damage.
Your interpretation is correct. This does cause AZ to deal himself a lot of fire damage but if he can sustain the hit than this is counteracted by his modules allowing him to heal himself for all the damage dealt (and then some with focused aperture). This makes for an extremely powerful Coolant Blast next turn. This is why I enjoy playing Absolute Zero ;D
Given that Coolant Blast is based on the amount of fire damage sustained since the end of his previous turn, I don’t think damage sustained from Thermal Shockwave would have any effect on Coolant Blast next turn.
You are correct! I misread this as the beginning of your last turn for some reason. I’ve never really played AZ until last week. That is slightly disappointing 
If you can either get Absolute Zero to have an addition power, or use a power out of turn, then you can reap some benifits from this.
Plus damage from any villain cards (such as the Gene-Bound Firesworn or Baron Blade’s “Slash and Burn”), and possibly some damage from a teammate, like Ra, or Expatriette with Incendiary Rounds, and then from a card such as Hoarfire . . . really, there’s a lot of potential there if you work it right. Trust me.