A method for inferring temperature in an enclosed volume containing a fuel/oxidant mixture, the method comprises placing at least one wire in the enclosed volume. The at least one wire having an identifiable property wherein the identifiable property of the at least one wire changes from a first identifiable state at a temperature below the auto-ignition temperature of the fuel/oxidant mixture to a second identifiable state at a temperature above the auto-ignition temperature of the fuel/oxidant mixture, and determining if the identifiable property of the at least one wire has changed from the first identifiable state to the second identifiable state and hence if the temperature in the enclosed volume is above the auto-ignition temperature of the fuel/oxidant mixture.