Return To Blog

The Dreaded Fever: Hot Tips to Understanding Why Your Temperature is on the Rise


By Jessica Kelner, D.O. - November 6, 2018

It's that time a year again. With the fall weather comes cold and flu season. We all know that being sick with a cold or the flu really puts a damper on your day. Especially when you get a fever. You may feel cold or hot, all wet and clammy, and your body may ache and hurt.  

Why do we get fevers anyway and what is a fever? 
First we should start off with what a cold is.  A cold is caused by a virus that you have come into contact with that usually gives you symptoms of an upper respiratory infection.   Our immune system is equivalent to our body's military.  Our immune's system's method of protection is complex. It goes through a chain of chemical processes that are specifically designed to kill the virus (or offending agent) and make sure it never comes back. The White Blood Cells (a component of the immune system) start to make antibodies to the virus. Antibodies are how your body remembers the virus incase it needs to fight it again.   When the White Blood Cell comes into contact with the virus, it also signals the production of a chemical mediator called interleukin-1, which is also known as a pyrogen. This chemical messenger binds to receptors in the hypothalamus that alter the body's temperature.  The hypothalamus, which sits at the base of the brain, acts as the body's thermostat.  Through the blood stream, the hypothalamus detects these pyrogens which can be produced by the body's tissues or even by some pathogens. When the hypothalamus detects pyrogens, it increases the body's generation of heat, thus producing a fever. Since children have more naive immune systems, they typically get higher fevers and quicker fevers.

If your temperature is altered by a virus, it is more likely to be elevated, but can be lowered as well.   The elevation of the body's temperature helps to make the body's environment uninhabitable for the invading virus. You may have an elevation of your temperature that isn't a fever (<100.5 degrees Fahrenheit).  This is not a fever. A fever is when your temperature rises above 100.5 degrees Fahrenheit.   So, essentially this fever is helping the body get rid of this infection faster.  

Having a fever is no reason to panic.  A temporary fever can actually be a good thing for your body, as long as you can tolerate how it makes you feel.  Fevers tend to make us feel very tired, hot, and make our body feel very achy. Just because your body's temperature is elevated, doesn't mean you have to go take medication to reduce it.  Medications like Tylenol or Ibuprofen are great at reducing fever and are generally safe to take if needed. 

For an adult, with adequate rest, hydration, and nutrition, usually a fever will pass as the body is able to fight the infection. 

If you have a fever, does it mean you have the flu? 
No, it does not.  You can have a fever with both the common cold and the flu.  The influenza virus ("the flu") is a specific virus that generally causes more severe symptoms than the common cold. This virus has an available vaccine that you can get annually at your doctor's office.  The influenza virus tends to change year to year, where as the common cold changes much more frequently.  This is why you can get a cold more than once within a few month period of time.  If you believe that you may have the flu, you should go see your Primary Care Doctor or Urgent Care physician for an evaluation and treatment.