Executive summary

Extreme heat is emerging as a structural economic risk, with Europe particularly exposed. Since the 1980s, heat stress events have multiplied sevenfold, and the average death toll per event has risen fivefold. Europe’s vulnerability is driven by ageing populations, dense urban environments designed to retain heat, and severely underdeveloped cooling infrastructure. Air conditioning penetration in Europe averages only 19%, compared to approximately 90% in the United States. The economic transmission of heat stress is non-linear, with a critical threshold at 30°C. Above this level, productivity losses intensify sharply, primarily through reduced labour output. Output per hour declines by approximately USD 1.30 for every degree across the 30–35°C range, which represents roughly 3% of mean hourly output in the study sample.

The economic transmission of heat stress

Global data illustrates a significant increase in the frequency and lethality of heat stress events. Between 1980 and 1989, only 14 heatwave events were recorded globally; this figure more than doubled in the 1990s and reached 99 in the truncated 2020–2024 period. Per-event lethality has also risen fivefold, from an average of 244 deaths in the 1980s to 1,222 between 2020 and 2024. This decoupling between event frequency and lethality indicates that the intensity and duration of heat episodes are increasing faster than societies can adapt. European countries, including Russia, Italy, France, Spain, and Germany, account for 68% of total recorded deaths.

The transmission of heat stress operates through two main channels: energy demand and labour productivity. The relationship between temperature and energy demand is U-shaped. Below 30°C, warmer conditions reduce heating costs. Above this threshold, cooling demand dominates and consumption rises by roughly 1.2% per degree. High temperatures also constrain energy supply; a large share of European generation depends on thermoelectric technologies like gas (51%), nuclear (18%), and coal (17%), which depend on water availability for cooling and suffer efficiency losses in extreme heat. Transport infrastructure faces similar pressures, with road networks accounting for 89% of heat-exposed assets and rail for 11%.

Labour productivity is reduced through physiological, cognitive, and sleep-related channels. Sleep loss due to high night-time temperatures reached a record 8.7% in 2024, with up to 12 additional hours of sleep lost per person in the most affected locations. Above 30°C, every degree beyond the threshold reduces output per hour by approximately USD 1.30. In contrast, temperate economies below the 30°C threshold may exhibit modest productivity gains.

The macroeconomic implications of heat stress

A stress scenario replaying the five hottest years between 2014 and 2024 over a five-year window (2026–2030) suggests cumulative GDP losses of 5–7% for the most exposed economies. Absolute losses are estimated at USD 354 billion for Japan, USD 240 billion for France, USD 147 billion for Italy, USD 131 billion for Germany, and USD 120 billion for Spain. Conversely, cooler economies such as Canada, Switzerland, and Sweden could see cumulative GDP gains of 1% to 3% due to reduced heating costs and marginally improved working conditions.

The macroeconomic cost operates through weaker household consumption and lower investment. Investment losses systematically exceed consumption losses because heat compresses expected returns on capital and reduces future productive capacity. For example, Italy faces an investment collapse of 12.8% alongside a 4.2% consumption loss. Furthermore, heat stress triggers stagflationary dynamics, with rising prices occurring alongside rising unemployment. This creates a difficult trade-off for monetary authorities, particularly in the Eurozone, where a single policy rate must serve economies with diverging climate exposures.

The fiscal burden

Extreme heat strains public finances by cutting revenues and raising adaptation costs. Annual revenue losses are estimated at 1.8% in France, 1.3% in Italy and Spain, and 0.7% in Germany. Revenues fall faster than output itself because progressive tax systems amplify the fiscal drag beyond the headline GDP loss. Simultaneously, public spending rises due to higher inflation-indexed transfers, healthcare costs, and emergency infrastructure repairs.

Heat-related spending accounts for approximately 2.1% of GDP in Europe. Fiscal balances are expected to deteriorate by an average of 0.5% of GDP annually. France is the most exposed case, where heat stress could worsen a projected deficit of 4.9% by an additional 2.2% of GDP. Italy and Spain also risk breaching the Maastricht deficit ceiling of 3% once heat-related pressures are factored in.

From exposure to resilience: the three-pillar adaptation plan

Closing the adaptation gap requires coordinated action across four fronts: labour regulation, buildings, public finance, and households. Pillar one focuses on protecting workers through binding temperature thresholds, automatic work restrictions, and compensation for lost hours. Currently, no major European economy meets all these criteria, and protections often exclude non-standard workers.

Pillar two addresses cooling buildings and grid stability. This includes implementing overheating thresholds in building codes and mandatory passive cooling during renovations. Pillar three focuses on income protection and adaptation finance. It proposes redesigning fiscal architecture to include explicit heat triggers for social protection and establishing multi-year adaptation budget envelopes. This would replace the current reliance on ad-hoc emergency packages, which consume fiscal space that should be used for proactive prevention.

Appendix

Empirical results confirm a non-linear relationship between heat and energy demand, identifying a critical threshold near 30°C. At 25°C, a one-unit increase in heat stress is associated with a 0.6% decline in per capita energy consumption, whereas at 35°C, the same increase leads to a 1.2% rise. Regression analysis also shows that the wage response materialises with a lag, with higher heat stress in one year associated with dampening wage growth in the following year, reflecting the slow transmission of productivity losses into labour compensation.