A wireless temperature sensor for use in monitoring the temperature of a fluid or gas in a mixing vessel. The wireless temperature sensor comprises a temperature probe for contacting the fluid or gas and generating a signal based on the gas/fluid temperature; a temperature reader for receiving the signal generated by the temperature probe and determining therefrom a temperature reading of the fluid or gas; and a radio frequency (RF) transceiver for transmitting the temperature reading determined by the temperature reader to a control apparatus external to the mixing vessel.