Relationship between characteristics of high temperature in summer and incidence of heat stroke in residents in Songjiang District of Shanghai, 2011-2017

ObjectiveTo explore the epidemiological features of heat stroke in Songjiang district of Shanghai, and provide scientific data for the prevention and control of heat stroke.

MethodsThe temperature data and case reports of heat stroke were downloaded from the weather forecast internet and China Information System for Diseases Control and Prevention, and the epidemiological investigation were conducted on all the cases to analyze the relationship between the daily maximum temperature and the daily average number of cases.

ResultsThere were 163 high temperature days totally for one year, which concentrated in July(58.28%) and August(38.04%), and 127 days(77.91%) were with heat waves. There were 256 cases of heat stroke, with an annual incidence rate of 2.51/10⁵, of which severe heat stroke accounted for 73.05%. Every day, 10:00 to 11:00 and 15:00 to 17:00 were the high incidence period. Among the cases, 79.69% were males. Their occupation were mainly builders (33.59%), workers (non-construction)(26.17%) and retirees(23.83%). When the daily maximum temperature was between 31-40℃, the daily average number of cases of heat stroke increased exponentially with the rise of temperature, and the number would increase 1.84 times per day when the temperature increased by 1℃. When the daily maximum temperature was between 35.0-36.9℃, with ordinary high temperature days, heat wave weather was more likely to cause heat stroke RR=1.93, 95%CI=(1.05, 3.52).

ConclusionHeat stroke in Songjiang District occurs mainly in July and August as high temperature days concentrate in these two months. High risk groups for heat stroke are mainly males, builders, workers (non-construction) and elderly retirees, for whom prevention and control of heat stroke should be enhanced in high temperature heat wave days.