Thermocouples are used extensively to characterize fire intensity and effects through the measurement of gas and/or solid surface temperatures in naturally burning wildland fires. These devices are rugged and portable; however, an analysis of the potential errors associated with their use in wildland fires reveals that accurate temperature measurements are difficult to achieve. In this study, the relative impact of thermocouple type, bead size, wire size, measurement location, and surrounding environment on measurement accuracy are explored. The relative contribution of radiant energy transfer, conductive energy transfer, and convective energy transfer to the sensor surface determine the measurement accuracy. Alternative sensor designs are readily available and properly selected can optimize measurement accuracy for specific measurement scenarios. The results indicate that measurement accuracy can be maximized through judicious selection of sensor design. Based on this study, specific sensor designs are recommended that will maximize measurement accuracy for several different situations characteristic to wildland fire.