Abstract: An example device includes: a print engine including a fuser; an ambient temperature sensor; a memory storing a plurality of curves that relate, for given respective ambient temperatures, respective time periods for the fuser to heat to a fusing temperature, to respective factors associated with cooling of the fuser; and a processor The processor is to: detect a current ambient temperature using the ambient temperature sensor; select a curve, from the plurality of curves, using the current ambient temperature; determine a current factor associated with cooling of the fuser; and control the fuser to heat to the fusing temperature based on a respective time period determined from the curve and the current factor associated with cooling of the fuser.