It happens... Though usually it's because you have ran longer than your gearing allows... On a brand new motor, I start checking temps every 5 mins... Even on my EB410.2 in 80+ degree weather, I can run almost an entire pack and never breach 140 degrees... No fan on mine or the ESC... Once you overheat a motor, the life span starts to shrink. If it is geared correctly, and you have data on a fresh build what works, if the temps start getting higher than your data, then you are having mechanical issues; binding in your diffs or somewhere else... I like having a temp gun for this reason.
Just my 2 pennies worth.
SS