Temperature dependence of thermal effect for neodymium doped yttrium orthovanadate crystal is quantified by measuring its dioptric power. With the boundary temperature range from 293 K to 353 K, the increase of fractional thermal load (lasing at 1064 nm, pumping at 888 nm) is from 16.9% to 24.9% with lasing, which is attributed to the rise of upconversion parameter and thermal conductivity. The influence of the boundary temperature on the output characteristic of a high-power single frequency laser is also investigated. The maximum output power decreases from 25.3 W to 13.5 W with the increase of boundary temperature from 293 K to 353 K. Analysis results indicate that further power scaling can be achieved by controlling the Nd:YVO(4) temperature to a lower.