The link between climate and health is nothing new. Thousands of years ago, Hypocrates and the Bible blamed the changing seasons and hot winds for some physical and mental problems. Today, these ideas without a clear scientific basis come together in a field of study known as medical bioclimatology. It studies how changes in temperature, pressure and humidity and atmospheric phenomena, affect people and their wellbeing.�

One of the atmospheric phenomena most often written about in terms of its effect on human behavior is the wind. There has been much talk of people living in areas whipped by hot winds going mad.� Indeed, research done in the late 1980s showed there was a link between hot winds and a rise in rates of suicide and aggressive behavior. It is thought the winds affect levels of seratonin, which is directly involved in the workings of the brain. Also, a strong wind known as the tramontana, which blows in Catalonia and the south of France, has also been known popularly to cause mental problems. Studies by general practitioners and psychiatrists have shown that at least two-thirds of the population suffer effects from these winds. Studies say behavior changes, although not necessarily for the worse, because the wind can stimulate both physical and intellectual activity. Again, the reason for the change is said to be an alteration of neutransmitters in the brain.�

Heat and cold are other variables that affect people's health. In addition to problems like heat stroke, which can kill, or low temperatures that lead to hypothermia and can also be lethal, the mercury also affects our behavior. A temperature between 17� y 30� C seems to be healthiest for people. Alleged links between heat waves and increases in violence and murder are well known. Part of this is just a legend. But excessive heat does increase stress and irritability. And the blood vessel dilation that occurs with heat affects both biochemical and neurological activity in people.

Sunlight is also important to health because it is essential for the synthesis of vitamin D and thus for the proper functioning of the body. Indeed, there is a syndrome called seasonal affective disorder that is linked to autumn and winter. It is believed that the shorter days and reduction in sunlight cause a hormonal and chemical imbalance the brain, causing feelings of sadness, difficulty in concentration, fatigue and other behavior disorders. It has also been shown that young women are the main victims of this disorder.

Then there is atmospheric pressure. Sudden rises and falls cause electromagnetic changes that the body perceives and reacts to. Up to 40% of the population are bothered by these changes, suffering from headaches and irritability right before a storm. Then, the number of positive ions in the lower layers of the atmosphere increases. Areas that are enclosed and have electricity are full of these ions, while places near the beach or mountains have more negative ions and are thus beneficial, allowing people to relax more. It is also known that climates which are cold and damp are not good for people with rheumatic conditions, while coastal climates, with their lower pressure, are good for cardiovascular patients because they allow for relaxation and calm.