Brutal heat waves are coming more frequently in Europe, leaving millions of people struggling to adapt to punishing, record-breaking temperatures.

There is little respite. Air conditioning is very rare in European homes. Many residents ride out the searing heat with the help of electric fans, ice packs and cold showers.

But Europe hasn’t approached heat in the same way as the historically hotter United States. While nearly 90% of US homes have air conditioning, in Europe it’s around 20%, and some countries have much lower rates. In the United Kingdom, only around 5% of homes have cooling systems — many of which are portable AC units. In Germany, the figure is 3%.

As climate change drives more severe and prolonged heat waves, which arrive earlier and earlier, some are questioning why wealthy European countries have been seemingly reluctant to adopt air conditioning — especially as the heat takes an increasingly deadly toll.

A big part of the reason is many European countries historically had little need for cooling, especially in the north. Heat waves have always happened but rarely reached the prolonged high temperatures Europe now regularly endures.