Common Cold, Cell Thermoregulation, Heterochromatin and Body Heat Conductivity

Common cold (CC) is an infectious disease of the upper respiratory tract. CC is considered one of the most widespread human illnesses and causes enormous harm to health and the economy. In the United States alone, CC leads to 75–100 million physician visits annually, with a conservative cost estimate of $7.7 billion per year. Americans spend $2.9 billion on over-the-counter drugs and another $400 million on prescription medications for symptomatic relief. The etiology of CC is known — over 200 virus strains are implicated in the cause of the CC, while bacterial infection is detected in only 5% of cases. As for pathogenesis, it is generally accepted that cold exposure plays an important role in the development of CC. It is believed that cooling reduces tissue resistance to infectious agents and lowers the body's defense against infection. However, it is evident that only a proportion of the people who are exposed to cold will develop an infection, and this finding suggests that there are other underlying factors that may reduce resistance to CC. Such factors can include: a) the initiation mechanisms of CC; b) the CC sickness rate (children get sick more often than adults) and gender (males are more susceptible to CC than females, regardless of age); c) not all people develop CC during the cold season, and finally, d) CC affects only humans and apes. It is proposed that at the core of these factors may lie the features of cell thermoregulation, heterochromatin and heat conductivity of human body.