What's is the difference between hot rolled steel roof and cold room steel roof?

No, hot and cold rolled steel is a manufacturing process. Warm and cold deck roofs refer to the location of the insulation layer within a roofing system. A warm deck roof has the insulation layer over the ply deck covering the ceiling joists. A cold deck roof has the insulation between and under the joists but must also include ventilation between the insulation layer and deck to prevent condensation building up.