Flew a SAR mission a fair few years ago on Bonfire night, trying to find some unfortunate old chappie in the dark. When the family was questioned about what he had been wearing it was black trousers, black hat and black coat. High probability find that one
Back to the thread, the hardest thing was creeping around at low level in the smoke! From a couple of hundred feet you could see, from the lights of the fireworks etc, a fantastic 'inversion' effect causing the smoke from bonfires to be trapped in a layer.
The rest was pretty much routine, try and fly over the displays as high as possible and in the search area try and avoid overflight of anything that looked like a bonfire.
After the search, negative unfortunately, we took a long, slow flight home and watched the fireworks. Spectacular I have to say.