Garfiel already has tanked a heat blast that would have vaped him and adapted fast enough so that it doesnt burn him to death instantly:
Lets do some napkin maths!!
we are gonna use the thermodynamic data for silicon (which underestimates oxide behavior and does not consider that cement has material with way stronger bonds), the latent heat of vaporization alone is 13.7 MJ/kg, with an additional 1.8 MJ/kg for melting. Including heating raises that total further.
taking:
Power, P=E/t=(1.37×10^7)/10^-3=1.37×10^10W
(here, we took time=10^-3 which is a very conservative number considering even the slowest of the verse can easily perceive supersonic to sub rel speeds. E as we previously established is 13.7 MJ/kg)
Intensity, I=1.37×10^10W/m^2 [Assuming a 1 m² interaction area]
Now using stefan-boltzman's law, which basically states that I=σT^4
(I is 1.37x10^10 and σ is 5.67x10^-8)
Taking the fourth root, we get T = 22,154k
so we get 22,000 kelvins bare minimum even with the lowest interpretations
Garfiel's heat resistance is not that far behind bakugou's explosions and especially not enough for him to be unable to adapt to it.