Are heat-related illnesses in SG a cause for alarm?

Unique features characterize the occurrence of heat-related illnesses, such as cramps, exhaustion, and stroke, among patients admitted to the emergency department (ED) of Singapore General Hospital, reports a recent study.

“These local contexts may be valuable to consider preventative measures for heat-related illness, in preparation for future extreme weather events related to climate change,” said the researchers.

From 2008 to 2020, a total of 426 patients (median age 32 years) had been diagnosed with heat-related illnesses among the 1,833,908 patients registered at the ED. Of these, 303 (71 percent) were male and 201 (47 percent) were foreigners. [Proc Singap Healthc 2024;doi:10.1177/20101058241232182]

Annually, the number of cases ranged from a low of 21 in 2019 to a high of 49 in 2015, with the exception of just four cases in 2020, the year of the pandemic. Most heat-related illnesses occurred on Sundays (n=233, 55 percent) and in December (n=97, 23 percent). Ninety-one of the 97 cases in December happened on the day of an annually organized marathon.

Nearly half of the people with heat-related illnesses were hospitalized, with 183 (43 percent) being admitted to the general ward and 31 (7 percent) to the intensive care unit. The number of deaths within 30 days was 2 (0.5 percent).

Non-Singaporeans

Notably, the findings revealed that about one-fourth of patients were from countries that have nontropical climates, such as East Asia, Europe, and North America.

It was not clear whether these individuals were travellers or residents in Singapore, but the results were consistent with the suggestion that people travelling from cooler climates must exercise caution, as mentioned in an advisory from the National Environment Agency in Singapore. [New Heat Stress Advisory Launched To Guide Public On Minimising Risk Of Heat-Related Illnesses 2023]

“These unique aspects may highlight the importance of implementing measures to prevent heat-related illnesses for special populations [not] adapted to hot and humid environment as well as typical cases of exertion-related illness like people working in outdoor settings during daytime,” the researchers said.

“Further, the results also suggested the necessity of preparing the ED for multiple cases related to special circumstances such as mass-gathering events or sports events,” they added.

Climate change

As the climate exhibits dramatic changes and as days with extreme heat weather increase, more cases of heat-related illnesses are to be expected, according to the researchers.

“Future research should consider conducting prospective studies to obtain more accurate and comprehensive data on the epidemiology of heat-related illnesses in Singapore, especially exploring the underlying mechanisms and risk factors associated with heat-related illnesses in specific population subgroups, which could provide valuable insights for targeted interventions,” they said.

The present retrospective observational study used electronic health records from the ED of Singapore General Hospital. The research team analysed patients primarily diagnosed with heat-related illnesses from 2008 to 2020. Subsequently, they described the annual number of cases and temporal trend of heat-related illnesses, along with the patient characteristics.