Wallonia recorded more heat-wave deaths than Flanders — and the gap is structural
Belgian health institute Sciensano's excess-mortality monitoring showed a heavier death toll in Wallonia than in Flanders during the summer heat episode, a gap researchers link less to temperature than to housing quality, population age structure, socio-economic deprivation and the reach of regional heat plans. De Morgen reported the divergence on 24 July 2026; Sciensano's Be-MOMO monitor remains the reference dataset.
Heat-wave deaths in Belgium fall overwhelmingly on people over 75, people living alone, and residents of poorly insulated housing — a population that is growing in both regions. The Wallonia–Flanders gap indicates that mortality is driven by housing quality, age structure, deprivation and the reach of social outreach rather than by temperature alone, which means it is amenable to policy. For anyone with an elderly relative or neighbour in Belgium, the practical takeaway is that the decisive factor during a heat episode is whether someone checks on them during consecutive tropical nights.
Sciensano is Belgium's federal public health institute; its Be-MOMO (Belgian Mortality Monitoring) system compares observed weekly deaths against a statistically expected baseline to produce excess-mortality estimates, the standard tool for measuring heat-wave impact. Belgium's health competences are split: the federal level runs the ozone-and-heat warning plan through the Nationale Cel Ozon en Hitte, while prevention and outreach are regional — the Agentschap Zorg en Gezondheid in Flanders, AViQ in Wallonia, and COCOM/Iriscare in Brussels. The Royal Meteorological Institute (KMI/IRM) declares a heat wave using its Uccle reference station. Urban heat island refers to the temperature surplus of built-up areas over surrounding countryside, driven by sealed surfaces and lack of vegetation, and is strongest at night.
Background
Belgium's heat-mortality monitoring dates from the aftermath of the August 2003 European heat wave, which caused roughly 15,000 excess deaths in France and several hundred in Belgium and prompted the creation of the federal ozone-and-heat plan. Sciensano (formed in 2018 from the merger of the WIV-ISP and CODA-CERVA) inherited the Be-MOMO monitoring system. The summers of 2019, 2020 and 2022 each produced measurable excess-mortality peaks, with the July 2019 record of 41.8°C at Begijnendijk still Belgium's highest recorded temperature.
What to do
During a heat warning, the single most effective action is checking on elderly or isolated neighbours and relatives, particularly after two or more consecutive tropical nights. Residents who need help can register with their municipal CPAS/OCMW social service, which maintains check-in lists in many communes. Keep shutters and windows closed during the day and ventilate at night; be aware that some cardiovascular and psychotropic medications impair the body's ability to regulate temperature — a question worth putting to a GP or pharmacist before a heat episode rather than during one.
Impact
Regional — Wallonia's older housing stock, higher income-deprivation rate and the dense terraced neighbourhoods of the Charleroi–Liège industrial belt concentrate heat risk. AViQ and municipal CPAS/OCMW social services carry the outreach burden. In Flanders, the Agentschap Zorg en Gezondheid coordinates the warmteactieplan, but the same ageing-plus-density dynamic is intensifying in inner Antwerp, Ghent and the Brussels periphery.
Opposing perspectives
- Walloon regional health authorities (AViQ)
AViQ and Walloon municipal social services argue that the region's outreach machinery functions as designed and that the mortality gap reflects structural conditions the health sector did not create — an older and poorer housing stock, a demographic profile weighted toward isolated over-75s, and post-industrial urban density. On this reading, closing the gap requires housing renovation and energy-poverty policy, not a redesign of the heat plan.
- Flemish public health researchers and climate adaptation specialists
Researchers working on Flemish heat adaptation caution against reading the figures as a Walloon problem. Their argument is that Flanders' relative advantage is demographic and material rather than institutional, and that dense inner-city districts in Antwerp, Ghent and the Brussels periphery are converging on the same risk profile as the ageing population grows. They press for active registers of vulnerable residents rather than voluntary telephone check-ins.
- Municipal social services (CPAS/OCMW) on both sides of the language border
Local social services point out that they carry the operational burden of heat outreach with staffing set for ordinary caseloads, and that identifying isolated elderly residents is hampered by privacy rules limiting the sharing of health and address data. Their position is that any improvement in either region depends on a legal basis for pre-identifying at-risk residents before the warning is issued, not on additional plans.
- Housing and energy-poverty campaigners
Organisations working on energy poverty argue that heat mortality and winter fuel poverty are the same problem measured in different seasons, and that both regions treat summer heat as a health emergency rather than a building-quality failure. They contend that renovation subsidies remain skewed toward homeowners able to co-finance work, leaving the badly insulated rental stock — where the risk concentrates — largely untouched.
Sources & evidence
- View sourceDe Morgen — Waarom er tijdens de hittegolf meer doden in Wallonië vielen en wat Vlaanderen daaruit kan lerenPrimary· demorgen.be· 24 July 2026Retrieved 24 July 2026· 2 days ago· Dated
- View sourceSciensano — Be-MOMO Belgian Mortality Monitoring· sciensano.beRetrieved 24 July 2026
- View sourceAgentschap Zorg en Gezondheid — Warmteactieplan Vlaanderen· zorg-en-gezondheid.beRetrieved 24 July 2026
- View sourceAViQ — Plan Forte Chaleur (Wallonia)· aviq.beRetrieved 24 July 2026
How this story developed
2 reports on this subject — earliest first. You are reading the highlighted entry.
- Belgium’s heatwave death toll exposes gaps in protecting older people at home
- Wallonia recorded more heat-wave deaths than Flanders — and the gap is structural· You are here
