Once my WF501B turned on accidentally in a backpack (3A on high). The drop-in was not wrapped in anything. Found it probably 30+ min afterwards it went on. Light was still very bright! 80 degree Celsius on the head. Measured with IR meter. I could not touch the head. Even the tail was too hot to touch for more than half a second. Luckily I had a lanyard attached to it and managed to turn it off and take out the battery once the tailcap had cooled enough.
XM-Ls seem to handle a lot of abuse around 3 amps!
When a light is too hot to comfortably hold, turn it down to medium or low.
If I go outside, there is little amount of wind and several minus degrees a P60 is barely able to function as a hand warmer while using it on high. Heat issues depend a lot on the environment. And no matter how hot the light gets with a 3A drop-in. The LED will most likely survive without issues is long as its in a P60 and the LED is attached properly to the pill. If you are able to hold the light, I would not worry at all about the LED.
I think people worry too much about heat issues. Especially when driving XM-L at 3amps or less. A P60 probably have much better heat sinking to the body than say a Nitecore Caveman.
When that is said. I normally aim for good heat sinking in combination with copper sinkpad. Just because, maximum output on high!
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