Is it true that if you walk around without a hat in winter, you can get meningitis?

Parents often scare their children with the fact that if you don’t wear a hat in the cold, you can get meningitis. We decided to check how great this danger is.

For the most part, the statement that not wearing a hat in cold weather can lead to meningitis is passed down by word of mouth, from parents to children. These parental threats are satirized in humorous show And memes. However, this opinion it's still possible meet even in Media and on television. Internet users ask questionIs this true? forums and in social networks. In the USSR, women's hats, almost not covering the head, were called meningitis — with the implication that those who wear them risk meningitis. 

First of all, it’s worth understanding what it is meningitis. This is an inflammation of the fluid and membranes surrounding the brain and spinal cord. Most often it is caused by bacterial or viral infections. Viral meningitis is the most common and relatively less dangerous. Its causative agents are mumps viruses, herpes viruses, enteroviruses, HIV, etc. From bacterial Meningitis kills every tenth person who gets sick, and every fifth person, even after recovery, has serious consequences. More than half of all deaths from meningitis in the world are caused by the bacterial type, and this despite the fact that it is much less common than the viral type.

Much less common are cases where meningitis develops due to other reasons: for example, fungal infection, cancer, head injuries, parasites (through polluted water bodies or contaminated food), etc. But hypothermia is not among them. Moreover, people most often suffer from meningitis in those countries where there is no frost at all. According to the US Centers for Disease Control, the highest incidence is in "meningitis belt" Sub-Saharan Africa.

“Freezing” the brain and thus getting inflammation will also not work: our body protects internal organs from hypothermia. Thus, blood vessels narrow in the cold, redirecting blood from the surface of the body inward, muscles begin to tremble, producing heat, and hormones are produced that speed up metabolism. So you're much faster frostbite keep your ears without a hat, which will “chill” your brain.

However, the incidence of meningitis in winter is really rises. Why is this is happening? Firstly, in winter we are more likely to get colds and flu, which reduce immunity and indirectly make our body more susceptible to pathogens. Secondly, we often spend time indoors with a large number of people, and this contributes to the spread of viruses and bacteria. So the easiest way to get meningitis in winter is not in the cold, but in a warm room.

Here it’s worth going aside a little and talking about why people get respiratory infections more often in winter - is it because they don’t wear hats and get cold? In the scientific community there is opinion, What immunity may decrease due to hypothermia. However, many believe that the body's ability to resist disease is much more affected by a lack of vitamin D due to little sun exposure (e.g. mortality from Covid was four times higher among those patients who were deficient in this substance). In addition, the cells of the respiratory tract are less active produce interferons (squirrels, which our cells produce in response to pathogens invading the body) when cold air enters them. But a hat will not protect you from this.

All reputable medical organizations (for example, US Centers for Disease Control, WHO, Canadian Meningitis Foundation) agree that the only effective way to prevent bacterial meningitis is vaccination, although it does not protect 100%. This is especially true for those who may potentially come into contact with patients or are planning to travel to countries where meningitis is most common. 

There is no vaccine against viral meningitis, so experts offer follow general recommendations for protecting against viruses: wash your hands more often, especially before eating, disinfect surfaces, and visit crowded places less often. And yet, among the preventive measures for not a single type of meningitis, warm clothing in cold weather does not appear.

Where did this myth come from? Yuri Zagvazdin, scientist from the Department of Physiology, Nova Southeastern University, USA, studied This question led to the conclusion that meningitis, or inflammation of the brain, had previously been associated with extreme temperatures, emotional distress and other factors. Scientists refuted all these versions at the beginning of the last century. Nevertheless, in Russian culture (and it was really not possible to find this myth in the English-speaking segment of the Internet), erroneous ideas are reflected in the works of Solzhenitsyn, Paustovsky, Pasternak and other writers. It is with this that Zagvazdin associates the spread of the opinion in Russia that meningitis can develop if you go outside in winter with a wet head or do not wear a hat. 

Thus, there is no direct relationship between frost and meningitis, except perhaps for some general decrease in immunity against the background of hypothermia and a person’s greater susceptibility to any viruses and bacteria. However, not a single authoritative medical organization names hypothermia among the reasons that can cause this disease, and does not include warm clothing, including a hat, in the list of recommended preventive measures. You won’t be able to “freeze” your brain either; the human body has a thermoregulation system that prevents this. But it’s easy to freeze your ears, so it’s still better to wear a hat in cold weather.

Not true

What do our verdicts mean?

Read on the topic:

1. Is it true that sitting on cold surfaces is dangerous to your health?
2. Is it true that reading while lying down is harmful to your eyesight?
3. Is it true that the body temperature of a healthy person should be 36.6 °C?