My understanding is that it has the same value as the "convert 8 heat into a raise temperature" action under more limited circumstances. It's only value would therefore be if the temperature is already maxed out or you want to spend 8 heat to gain a TP without increasing the temperature.
The thing I failed to realize is that because this is an action you can do it every turn too. So actually a useful heat dump.
Actually, you can't. You can only do it once per generation (round).
Right - by turn I meant to say generation, following the typical blue card rule. For some reason I originally interpreted it as a one and done effect so it was the realization that you could repeat the effect at all that prompted my comment.