Flew light aircraft for 15 years in Southern England, then moved to SA. In transitioning my license to the local version, my first hot and high departure (in the Karoo @ 3,500 AMSL, 30C) with my instructor sat next to me in a smartish 172R left me dry mouthed. Numbers done twice as per POH and checked again. Safety factors added. But still your mind does not quite accept what is happening and boy 1300m of firm gravel runway never quite seemed enough.
Pilot DAR and BPFE are, as ever, spot on with their post lift off advice
One other gem I would like to offer is do your power check on the firmest bit of ground you can find (common sense I know anyway). Here in SA many bush strips have a concrete area where you can get your power check and mixture setting sorted avoiding (well maybe minimising potential for) foreign object damage to prop and aeroplane whilst playing with the mixture knob.