Heated mattress is an optional local heat source for treatment of hypothermic states of patients. The unified design of the device enables its application almost in all fields of health service, intensive and reanimation care units, surgical departments, operating rooms, resuscitation departments, gynaecology, internal medicine departments, birth, children?s and neonatal departments. The main functional parts are electronic temperature regulator and patient?s mattress. The regulator maintains the temperature according to required parameters and provides a constant diagnosis of the circuits. The heated mattress with a built-in heating system, a set of temperature sensors and a thermal mechanical fuse is connected to the regulator through plastic connector with a safety nut. Low supply voltage of the mattress of 9V / 18V depending on the size provides the high operating safety. The required operating temperature is set-up with the keys on control panel. The set-up data are represented by the red LED display. Excess of the set-up temperature and a possible regulation failures are signalled by optical and acoustic alarms. This always results in automatic disconnection of heating. Therefore the uncontrolled increase of temperature and the patient injury is prevented.