I know. That's what I thought I said. I stated that the calculation will give a lower power than actual (therefore actual is higher than the calculated value); in the second part of the sentence I stated that the power and temperature are less when powered from a lower voltage [than when powered from a higher voltage]. At half voltage, the power is lower than at the rated full voltage, which means lower temperature and lower resistance [than full voltage]; this means the power at the lower voltage will be higher than calculated [with assumed constant resistance]. I concede that my sentence wasn't explicit or necessarily unambiguous.