I haven't really noticed this yet. I have now tested the lamp: Switched on at room temperature for 16 minutes at level 3 of 4. I couldn't detect any heat development on the handle. At the very front of the LEDs, it only got barely noticeably warmer.
I also used the lamp for about a week in the evening in the dark during walks. It was switched on for about 30 minutes at a time when the outside temperature was around 4 degrees Celsius. In this situation, it got a little warmer at the front of the LEDs, but nothing to worry about.
There is a warning on the front of the lamp ("hot"), but so far I have never had to pay attention to it.