A very strong El Niño is coming: is Australian general practice ready?

The World Meteorological Organization forecasts the tropical Pacific reaching a seasonal average Niño3.4 anomaly of about 2.0°C between July and September this year, and NOAA's July diagnostic discussion put the odds of a very strong event peaking between October and December at 81%. The International Research Institute for Climate and Society tracked the weekly Niño3.4 index climbing to 2.1°C by mid July, describing the event as evolving toward very strong, the kind sometimes called a super El Niño in the media, though that is an informal label rather than a formal one.

In Australia, El Niño years mean less rain, hotter days and a higher chance of drought and bushfire across the east and south. Extreme heat is already widely recognised as this country's deadliest natural hazard. The Australian Institute of Health and Welfare found extreme heat caused 7,104 of 9,119 directly attributable extreme weather injury hospitalisations, about 78%, over the decade to 2021 to 22, and that bushfire related hospitalisations happen 1.6 times as often in El Niño years as in La Niña years.

The hidden burden of heat

Those hospital figures are only the visible tip of the problem. A Lancet Planetary Health analysis of Australian mortality data found that officially recorded heat deaths capture only a fraction of the real toll, with modelling suggesting heat attributable mortality could be around fifty times higher than the number recorded on death certificates. Almost none of that hidden burden turns up as heat stroke in an emergency department. It looks like dehydration, a fall, a medication gone wrong, or a slow decline in someone with heart failure or kidney disease, quietly managed, week after week, in general practice.

Heat is hard on the body in ways that touch nearly every chronic disease GPs manage. A Lancet review of the health risks of hot weather links heat exposure to worsening heart failure, arrhythmia, heart attack, stroke, poor sleep and declining mental health. During the Black Summer bushfires, a Medical Journal of Australia study estimated the smoke was responsible for 417 excess deaths, 1,124 cardiovascular hospitalisations, 2,027 respiratory hospitalisations and 1,305 asthma presentations to emergency departments in a matter of weeks. An Australian scoping review found strong evidence linking heat to worse outcomes for people with mental and behavioural disorders, cardiovascular disease, diabetes and respiratory disease, exactly the patients who fill a general practice waiting room. Diabetes, chronic kidney disease, Parkinson disease, dementia and multiple sclerosis all become harder to manage once hydration and temperature regulation are compromised, and a number of commonly used medicines raise the risk further, something a recent Australian Journal of General Practice paper covers well.

Despite all this, there is currently no nationally coordinated, systematically funded heat preparedness framework for Australian general practice, in the way there is for influenza season. Hospitals plan for heat. State heat health alert systems exist. But the place where most of this illness is actually managed, quietly, over weeks rather than in a single emergency, has largely been left to work it out practice by practice.

What we can learn from influenza season

There is a template already sitting in every practice's calendar: influenza season. Each year, general practice runs a proactive, whole of population campaign built around identifying at risk patients, recalling them, and reviewing their care before the virus arrives, not after. Heat could be treated the same way.

That means using clinical software to flag patients who are older, have relevant chronic disease, or take medicines that increase heat vulnerability. It means SMS or telehealth outreach timed to Bureau of Meteorology heatwave warnings, hydration and medication sick-day plans reviewed before summer rather than during a heatwave, and continuity of care plans for bushfire smoke and power outage disruptions. None of this is complicated or expensive. It is largely a matter of deciding, as a system, that it matters.

What would help most is leadership from the top: the RACGP, Primary Health Networks and state health departments building heat preparedness into general practice the way they already have for influenza, rather than leaving each practice to improvise. Practice accreditation standards could incorporate climate resilience. Research could test whether proactive general practice outreach actually reduces heat related hospitalisations, something we currently do not know with any confidence.

Australia prepares its hospitals for disasters. It should also prepare general practice, because that is where many patients first present with climate related illness, and where much of it can still be prevented. With a very strong El Niño developing, this is a task for this spring, before the heat arrives.

Bernard Shiu is a general practitioner and Clinical Director of Banksia Medical Centre in Geelong, Victoria, and an Affiliated Associate Professor at Deakin University.