Yes, hot and cold working are common metallurgical terms. The hot work temperature is where the material does not strain harden or recovers while being deformed. In most cases, the working temperature at or above post weld heat treatment temperature is an excellent guide. So, for example, for SA 516 or any of the boiler tube materials if working is performed at a temperature at or above the PWHT temperature this would be hot working. Cold working would be below this temperature but some consider this as warm working. Either way, use the PWHT temperature as a guide.