title_body: How hot is too hot when it comes to multirotor motors? I hear this question asked all the time.  Are my motors getting too hot?  How hot is too hot for motors to get?  Anyone have a great way to answer this question, possibly with some temperatures?
  
  I generally go by feel.  If I can pinch the motors with my fingers for at least a few seconds without feeling like they will burn me, I know the motors are not too hot.  I know a lot of people would like a more scientific answer than that.
upvoted_answer: Temperature is a killer of motors over time. If motors are exposed to prolonged heat, the magnets in the rotor lose their magnetic field strength over time and consequently reduce the lifespan of the motor.
  
  Generally, a well-tuned drone should not have extremely hot motors after flying (with a few exceptions). It depends on the motor, but you should avoid raising the motor’s temperature past 170°F; any hotter, and you run the risk of damaging the rotor’s magnets and decreasing performance and longevity. 
  
  https://dronenodes.com/drone-motors-brushless-guide/
  
  https://www.rcgroups.com/forums/showthread.php?1329288-Normal-brushless-motor-temperature-range