ELI5 Why heat waves affect Europe so much but some other countries are doing fine living under hotter temperatures most of the year?

I read yearly that people are dying in Europe due to the extreme heat, but when I check the temperature mentioned in the same news it's something like 30-35c. Just saw this today: "In France, officials reported at least seven deaths linked to the heat, including several drownings and fatalities during sports activities (...) temperatures have broken records for the month of May, soaring well over 30 C (86 F) in many parts of the country." This is like a pretty mild day in a country like Thailand, India or in the Arabian peninsula. People are doing just fine in these countries, and many don't even have aircon. Why are such temperatures so deadly in Europe?