Method, apparatus, and computer program product are provided for determining a maximum temperature to which a perishable good or other temperature sensitive item was exposed. In some embodiments, a capacitance of a circuit provided on a substrate is measured. The circuit includes capacitor(s) each having first and second plates separated from each other by an ionic liquid (IL) in a solid state. The IL melts at a predetermined temperature and flows away from the first and second plates into a void. In some embodiments, the predetermined temperature at which the IL melts is different for each capacitor. For example, each capacitor in the circuit may employ a different N-alkyl bezothiazolium salt. A maximum temperature of exposure is determined based on the measured capacitance. In some embodiments, a decision of whether to discard the perishable good or other temperature sensitive item may be based on the determined maximum temperature.