Device overheats, Xcode shows low energy impact

Xcode shows a low average energy impact but my test device (iPhone 6s Plus) significantly heats up while application is active. Might be a bit nit-picky problem, but worries me that I'm doing something inefficiently. Is this a problem, and if so what is the best course of action to debug?

Device overheats, Xcode shows low energy impact
 
 
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