Question:
Another thing I noticed about this test reading further is that it was just a strofoam head. So all this test measured was the ability of the helmet to get rid of the heat it absorbed from an external source. There was no heat from the 'head' that needed to be shed to the environment. I mentioned nothing about heat stroke. Only that the styrofoam cooler anology was faulty.

Should I crack out the heat and mass text and do an analysis? This is not religon, its simple heat transfer. Your (good) experiment showed a definite difference in heating between bare head and helmeted head and that difference was there even with a windstream.

Tho pointed out that his head was hotter in a helmet than without one. In a study that the summary stated showed that helmeted heads cooled equally well to bare heads (note this Richard) the real information contained within the complete study showed that helmeted cyclists doing moderate exercise regimes in controlled conditions stated that their heads were hotter with helmets than without. The charts also showed that helmeted cyclists had higher heart rates than un-helmeted cyclists thereby backing up the claim of these cyclists.

You may also do a simple experiment. When you are cycling and sweat if pouring off of your head into your eyes, try taking off your helmet and riding bare headed. Does the sweat stop pouring into your eyes? Why would that be?

Answer: the rider numbers have decreased even more, so everybody still riding a bike after the helmet law has a higher risk of sustaining a head injury. Most of those who are seriously injured have been found to have been doing something REALLY stupid on bicycles such as riding at night without lights and often intoxicated. Or running stop lights on busy streets. Or riding on the wrong side of the road or on sidewalks where people pulling into driveways miss them or misjudge their speed. 30% of them are children who have a far greater chance of head injuries because children are already head heavy and because they don't know how to fall yet. So a normal experienced bicyclist stands a very much smaller chance of encountering a serious accident simply by riding in a normal vehicular and legal manner.

Another part of the puzzle isn't just head injuries, but the results of those head injuries. Only something like 1% resolve badly. That is to say that almost all bicycle related head injuries respond to treatment and theropy. Even the worst case normally return to almost normal lifestyles. This, unfortunately, can't be said for car and motorcycle victims of such injuries since they generally occur at higher speeds and with more serious consequences.

Serious head injuries are really rare. In the entire US bicycling related head injuries account for about 2% of the vehicular related head injuries and less than 1% of the overall injuries. Bicyclist are not in much danger of a serious head injury such as seems to motivate you. People talk about these injuries because the very worst things that you can imagine sometimes happen to people who are brain injured seriously. Well, injuries are rare in airline crashes and fatalities are the rule. But that doesn't make airline travel dangerous -- because any accident is exceedingly rare and scheduled airline traffic is the safest form of general transport.