This might do it for high temperature Over-Unity Heat from an electrolysis cell.
"FLAME TEMPERATURE"
"Flame tests in an argon atmosphere directed on several layers of carbon fiber fabric with its micron size filaments (Used on the stealth fighter & bomber.) melted carbon filaments into brilliant globules. This means carbon's melting temperature 3550C/6422F is exceeded, but its boiling point 4827C/8720F is not attained. Past that point no reference exists."
Frederick
