The heatwave that hit Germany in late June caused over 4,000 deaths, according to preliminary estimates from the Robert Koch Institute. With this toll, the number of heat-related fatalities in the first half of the year exceeds 5,100.

Between June 22 and 28, nearly 22,000 people died in the country. Without the extreme heat episode, the RKI estimates that about 17,500 would have died, representing an excess mortality of over 4,000 people. The institute also recorded another spike in deaths during a May heatwave.

The RKI notes that heat is rarely listed as a direct cause of death, except in cases of heatstroke. In most cases, death occurs from the combination of high temperatures and preexisting conditions, so the impact of heat is calculated through statistical methods.

The elderly were the most affected. Mortality increases significantly from age 75, with nearly 3,000 of this year's estimated deaths among those over 85. About 300 fatalities were also recorded among those under 65, though the RKI warns this figure carries a wide margin of uncertainty.