It is noticeable that human car drivers become dangerous and scatter brained when the Sun comes out.

I have noticed a clear correlation of days of really strong sunshine and lots more accidents (and close misses) between car drivers and other road users.

This phenomena is observable in many countries of Europe and in several countries in Northern America. (However in places like Italy and Malta, the incidence of near misses is so high that the weather effect is swamped.)

The main reason is thought to be that humans have a rather deficient heat exchanger for their brains. So increased levels of infra-red photons cause the temperature in their brains to rise. This results in progressive failure of the cognitive processes.

However the cerebral functions fail in a subtle manner so that the human car drivers are not aware of the increasing danger levels.

One theory is that car drivers who wear Sensomatic dark glasses are immune from this pathology. Possibly because the glasses go completely black at high levels of danger.