My son has fever, and I told him that it is his body’s way of defending itself against the viruses. However, he is six years old and asked me how increased body temperature would defend him against a virus.
Me, being forty, went: “… well… ehm… pff…”
Please dopers, help me out on this one.
chemical reactions generally go faster the higher the temperature. the cells in your body do zillions of chemical reactions to stay alive and do what they do. the chemical reactions that are part of the immune response are sped up by fever. your body increasing its temperature puts these actions into high gear.
But wouldn’t the virus also go into high gear from the increase in temperature?
I think the high temperature is a result of the immune system’s activities, not a separate event that triggers the immune system.
From here:
I had the vague idea that some viruses or bacteria can’t live at higher temperatures and so the fever helps kill them. Wikipedia mentions this as being a way in which fevers “may be useful”, but it sounds like this isn’t the primary way in which a fever helps fight illness. “Some viruses don’t like being hot” seems like an explanation that would satisfy a little kid, though.
**johnpost **inspired me to tell him that the blood vessels which fight the virus are getting faster when the body is hot, and so the body is heating up to increase their speed; and then I did a simile with Bakugan, which fell in good earth, I now he is asleep again, more comfortable with his fever. Thanks.
But nonetheless, I’d appreciate if the discussion continued, because it is interesting and when he is his normal self again, I might be able to explain it more (scientifically proven) detail.
To paraphrase Parham’s The Immune System, primary immune responders (neutrophils, macrophages) release cytokines that act on temperature control sites in the hypothalamus and on muscle and fat cells to increase metabolism and generate heat. Most viruses and bacteria grow better at temperatures lower than body temperature and the adaptive part of the immune system functions better at the higher temperature. So, “at elevated temperatures, bacterial and viral replication is decreased, whereas processing of antigen is enhanced.”
Note that the heat doesn’t *kill *existing attackers, just slows down their reproduction.
This is somewhat misleading as it is possible to experience fever without a corresponding increase in WBC activity. The increased WBC count does not cause the fever, but is part of the body’s multi-pronged attack strategy for fighting infections.
That is retarded.
Fever impedes bacterial growth (I doubt, tho, it affects viruses). Why wouldn’t bacteria just adapt to live at a higher temp?, you might ask. Good question. It’s because the vast majority of infections do not, as is commonly believed, produce fever or other symptoms, so bacteria evolve to be optimized for 98.6.
Edit: since high temperatures hurt human cells too, I can see how that would impede viral growth as well (since viruses breed through us).