Why does macbook air go to sleep spontaneously?

I do have a hot corner — bottom left, but that is not the problem. It sleeps when I'm nowhere near this corner.

I have reset the SMC on other Macbooks, but the Macbook Air battery is not user removable. I'm still under warranty, so I'll take it in to Apple in Pentagon City.

Thanks. This may have solved the problem. Will know for sure in a few more days.

I believe the problem is solved.

I read that placing an iPad on the right of a Macbook can cause the latter to sleep.

"One notable area where Apple has made use of this technology is in its MacBook laptops, where magnets and magnetic sensors in the chassis and lid bezel activate when in close contact, so the system will automatically go to … "