Computed and Measured Core Temperature of Patients With Heatstroke Transported From Their Homes via Ambulance

The number of patients experiencing heat-related illnesses has gradually increased due to global warming. Owing to an aging society, 50% of patients with heat-related illnesses in Japan are elderly. Core temperature is one key parameter for health care; however, its monitoring is virtually impossible. Internet of Things (IoT) devices for healthcare have been proposed; however, the vital parameters to be monitored remain controversial. Here, we assessed the core temperature of elderly patients who were transported to hospitals by ambulance from their homes. The patients’ core temperatures were recorded by the Fire Department of Nagoya City in the summers of 2019 and 2020. The time course of the core temperature of each patient was then replicated using the integrated computational techniques through multiphysics analysis and thermoregulation under ambient condition data. According to the statistics, most elderly patients who were transported from their homes had a high core temperature. The measured core temperature in 31.4% of the patients was higher than the computed core temperature even assuming that there was no sweating. Assuming that the sweating function works well, the total amount of water loss was insufficient to have caused dehydration in a single day. These results suggest that successive heat stress during the preceding days should be considered to recreate the computed core temperature to match the measurement. These results were consistent with the previous finding that some elderly suffered from heatstroke successively over a few days. In the IoT-based monitoring system development, it would be informative for monitoring core temperature during the preceding days.