The heat index reached 152 degrees in the Middle East — nearly at the limit for human survival

As the Northern Hemisphere approaches summer’s peak, heat is testing the limits of human survival in Earth’s hottest spots — and demonstrating the extremes that are increasingly possible and probable against the backdrop of accelerating global warming.

In recent days, China set an all-time high of nearly 126 degrees Fahrenheit, while Death Valley hit 128 degrees, two shy of the highest reliably measured temperature on Earth. Phoenix experienced a record-breaking 19th consecutive day at or above 110 degrees Tuesday. And in the Middle East, the heat index reached 152 degrees, nearing — or surpassing — levels thought to be the most intense the human body can withstand.