Thermal Responses Of The Elderly During Heat Wave And Cold Period

In recent years,as global warming has not slowed down,the global average temperature has reached record highs and the environmental temperature has changed drastically.The impact of environmental temperature changes on human health has become a research hotspot.Meanwhile,many reports have found high mortality rates among the elderly during heat waves and cold waves.Heat stroke during heat waves and hypothermia in cold environments are the main causes of high mortality in older adults,but there are no studies on the time course and factors influencing the development of heat stroke and hypothermia in older adults.In this paper,based on the classical thermoregulation model of Stolwijk and the improved thermoregulation model of healthy young people by our group,we established a thermal regulation model for the elderly applicable during high-temperature heat waves and cold periods by considering the effects of aging on the thermal physiological parameters of the elderly and the changes in the active control system of the elderly.The model was also used to simulate the change curves of core temperature of the elderly with time during high temperature heat waves and cold periods.The main results of this paper are as follows:(1)The core temperature changes of the elderly during both heat wave and cold periods can be divided into three phases,and the core temperature changes are greater than those of healthy young people.(2)The higher the ambient temperature or relative humidity during heat waves,the faster the core temperature rise;reducing medication use and timely drunk water can slow down the core temperature rise.Long-term exercise habit can improve sweating function,enhance the thermal regulation ability of the elderly,slow down the rise of core temperature and reduce the risk of heat stroke.(3)The lower the ambient temperature,the lower the relative humidity,the lower the thermal resistance of clothing or the higher the air velocity rate,the faster the core temperature will drop and the greater the risk of developing hypothermia.(4)Low temperature exposure can lead to vasoconstriction and elevated human blood pressure leading to cardiovascular disease from increased mortality.The thermal regulation model for the elderly developed in this paper predicts the time to develop hypertension during the cold period and helps to reduce the risk of death in the elderly.The thermal regulation model developed in this paper can be used for risk assessment and comfort evaluation of heat and cold-related diseases during heat waves and cold periods in the elderly population,and has important public health implications in the prevention of heat stroke and hypothermia.