This mathematical formula defines the change in temperature (ΔT) of an object over time as equal to the net rate of heat transfer into the object divided by its specific heat capacity. The net rate of heat transfer is calculated as the sum of the rates of heat transfer by conduction, convection and radiation, minus the sum of the rates of heat transfer out of the object by the same three mechanisms of heat transfer.

2. = ∆ = −
→ = ( )
+ ( )
+ ( )
−( ( )
+ ( )
+ ( )
)