As summer approaches, Coasties may notice a surge in young children needing hospital care during extreme heat.

A new study by the University of Auckland reveals that when temperatures exceed 24.1 degrees Celsius, hospital admissions for children under five increase across New Zealand.

The study, led by the university’s Faculty of Medical and Health Sciences, analysed 20 years of data on daily maximum temperatures and over 647,000 hospital admissions for young children.

The researchers found a strong link between high temperatures and various health conditions, including infectious diseases, skin disorders, and kidney issues.

Dr. Hakkan Lai, a senior research fellow in epidemiology at University of Auckland, explained, “We see hospital admissions increase as soon as the temperature rises, with effects lingering for up to three weeks afterward.”

He attributes this to dehydration, cardiovascular strain, and inflammatory responses, which can overwhelm children’s bodies, potentially worsening existing conditions.

Dr Hakkan Lai. Photo: William Chea

Young children are particularly vulnerable to heat due to their faster metabolism and smaller bodies, which heat up more quickly than adults.

The study also highlighted the uneven impact of heat on children across New Zealand, with children in regions like Central Otago, Central Canterbury, and the East Coast showing higher sensitivity to temperature changes.

Ethnicity, socio-economic status, and geography all played roles in children’s vulnerability to heat.

For example, Pacific, Asian, and Māori children had higher admission rates with rising temperatures compared to their European counterparts.

Additionally, children living in rented homes were more susceptible to heat-related hospital visits than those in owned homes.

Over the past seven years, approximately 290 heat-related admissions have been recorded annually, with the potential to rise significantly as temperatures increase.

Dr. Lai estimates that a 3-degree rise could lead to 1,300 admissions per year.

“With climate change, this issue will likely become even more pressing for our healthcare system,” Dr. Lai said, emphasising the need for informed planning and interventions. He hopes to expand his research to further explore the impacts of heat on New Zealand’s children, with the goal of helping communities prepare for a warmer future.