Most people flee, including Qataris. The government tries to persuade them to stay so there's this 'Summer Wonders' festival in the malls with music and stuff. Movies, too, of course. However, you won't meet or see many Western kids until September.
It's not just hot, it's humid.
So long as you've got a comfortable home and car with good ACs, you'll be OK, but Western-style socialising you won't get.