Dozens of people have been hospitalised for heat-related illnesses as the summer's first major heat wave descends on eastern North America. More than 150 people fell ill at an outdoor school graduation ceremony in Paterson, New Jersey on Monday, according to US media, as the city's mayor declared a state of emergency.

The scorching heatwave, the first major heatwave of the summer, is rapidly growing stronger across the eastern half of North America, triggering a range of health alerts and disrupting daily life for millions of individuals.