Heating a 10W, 22-ohm ceramic resistor on a standard perfboard
75 C ought not to damage perfboard even if it is a cheap and shoddy material. Had you said 95 C, I'd recommend placing an electrically and thermally insulating material underneath the resistor. A few layers of Kapton tape stuck to the perfboard would suffice, or if you want something that looks a bit nicer you could mill a resistor-width groove in a piece of PTFE, sandwiching it between resistor and board.