Variation of ear temperature when walking outside in summer

• When walking outside, ear temperature increases and decreases repeatedly.
• The increase in ear temperature was large in subjects whose ear temperature was low.
• It was confirmed that airflow is important for normally thermoregulation.
• The ear temperature tended to decrease during the rest.
• There is a possibility of risk in cases judged to be safe according to WBGT.

To achieve a truly “urban environment where people can live and walk”, global warming and the urban heat island may present serious challenges. Understanding the nature of changes in human core temperature is important if we are to plan for people walking in the urban outdoor thermal environment, considering the potential for heat stroke.The present study was performed to investigate changes in ear temperature and relationship of ear temperature and WBGT when walking in a real city environment. Ear temperature was measured in subjects walking in an outdoor city space in summer. When walking outside in the summer, ear temperature increases and decreases repeatedly. Measurement of ear temperature when walking in environments of WBGT 24 °C and 30 °C indicated no relation in the amount of WBGT and the maximum value of ear temperature. There is a possibility of heat stroke risk in cases judged to be safe according to WBGT.