If the environmental temperature is higher than ambient, then how hot will the CRA series get under power? The matrix on this slide shows actual recorded temperatures of a CRA2512 resistor which is rated to 3W maximum when powered to just 30%. At 85°C, the temperature of the part rises to 101°C. For designers who require small SMD current sense resistors with a power rating of 1W and a temperature derating starting from 80°C, the CRA2512 is a good solution.