[sup]Don't forget thermodynamic energy exchange[/sup]
Fire burns at 3,542 degress Farenheit.

Burning pain at 111 F, First degree burns at 118f
Second degree burns at 131 f
Pain receptors overload and become numb at 140f.
At 162 f human tissue is destroyed on contact.
250 f - Cotton Ignites

Third Degree Burn with Water
150 - (2 second) 
140 - (6 second) 
130 - (30 second)