How did Frankenstein survive

Sometimes Hammer didn't give detailed continuity explanations. Since they had intended to launch a new Frankenstein series after MUST BE DESTROYED (the Ralph Bates vehicle, HORROR OF FRANKENSTEIN), when it was decided to go back to Cushing as the Baron, they didn't tie this in closely with the previous Peter Cushing film. (Then again, how did Cushing go from being Dr. Franck in London at the end of REVENGE OF FRANKENSTEIN to being back in the Rhineland at the opening of EVIL OF FRANKENSTEIN?) My feeling is that they left his escape to our imagination. However, he didn't completely escape the flames...we see the Baron's hands are so badly scarred that he can no longer do delicate surgery.

It Dosen't Say But Hey Remember in The Evil of Frankenstein When Baron Frankenstein was Trapped in the tower and then it Exploded You would Think That He Died But In The Next One Frankenstein Created Woman He just got Scarred Hands with Gloves on them and he winces in pain sometimes and then in Frankenstein Must Be Destroyed His Hands are Perfectly Fine "Surely Scars Don't Heal That Fast" and then he is suposedly killed by fire and then the next one
Frankenstein And The Monster From Hell His Hands Are Burned It's Kind of like a Cycle and in this one he doesnt die Hammer Films Left him Alive
Basically He Should Have Died in Evil of Frankenstein

Plot hole