Various embodiments of the invention include systems for controlling cold-reheat extraction in a turbomachine system. Some embodiments include a system having: a high-pressure (HP) turbine section including an exhaust; a reheater conduit fluidly connected with the exhaust of the HP turbine and a reheater, the reheater conduit for passing HP exhaust steam from the HP turbine section to the reheater; a cold-reheat extraction conduit fluidly connected with the reheater conduit upstream of the reheater and downstream of the HP turbine section exhaust; and a control system coupled with the HP turbine section and the cold-reheat extraction conduit, the control system configured to: obtain data about a temperature of the HP exhaust steam; and provide instructions to modify a flow rate of the HP exhaust steam to the reheater in response to the temperature of the HP exhaust steam exceeding a threshold.