I remember one time I was working at a large hospital, and about 1 am a mother brought her toddler in with a rectal temperature of 106.5. Even for those of us who see a lot of kids with fever, that’s pretty high. We did a full evaluation including blood work, x-rays, and lumbar puncture and got the kid admitted to the pediatric service while we waited to see if the blood cultures grew anything. This child did fine and went home after a couple of days. Fevers continue to be one of the most common reasons people come to the hospital or see their doctors, especially in the pediatric age group.
I like to educate people about fevers because there are so many misconceptions. Everyone’s grandmother has an antidote for fever. Everyone knows someone who knows someone whose “brain was fried” due to fever. So many myths, so little time…
Aside from some unusually high fevers, usually caused by issues other than infection (discussed in the next blog), fever themselves are not dangerous. The cause of the fever, the infection, can be serious, even fatal, but it’s not the fever itself that leads to a bad outcome.
When we have an infection, our body responds to that attack with these inflammatory mediators to help fight the bacteria or virus. They tell our hypothalamus, which functions as our body’s thermostat, to reset our desired temp from, say, 98.6 to 102.5. When that new desired temperature is dialed in, we respond with body shakes, like chills, to increase our core temperature. The thought is that our body can survive at the higher temperature, but the virus or bacteria will struggle.
No one has really proven that we get better faster by not treating a fever. Since it’s usually that fever that make us feel poorly, anti-fever medications like Tylenol and ibuprofen become our best friends.
There are aspects of a person with fever that will cause us to take a closer look to make sure that the fever is just a fever and not a big deal.
In our next blog, I discuss some of those non-infectious causes of fever, things you maybe never even knew were a thing! And, I’ll share with you some trick of the trade for what to do when you or your family member has a fever.
Check out the full video transcript here:
Hey, guys, Dee Bonney here. I want to tell you a story about one time when I was working at a large tertiary care hospital. It was, I don't know, midnight, 1:00 AM, and a mom brought her kid into the hospital for fever. Not uncommon, right? Well, the charge nurse was working out in triage and she ends up taking this kid's temp rectally. I think he was like 15 months old. She ends up taking his temperature rectally and it was 106.5. Now, how many of you as parents would freak out if your kid's temperature was 106.5? I trained in pediatrics and in emergency medicine, so I'm pretty comfortable with kids, with fever, with everything in between, but 106.5 rectal temperature, it got my attention.
So this kid gets brought back to our more monitored area because we don't really know what to do with the temperature that high in a kid who otherwise seems okay. So I did some initial labs and workup and called the pediatric team to get the kid admitted just because something was going on and it's such a high fever. Normally, the degree of fever doesn't really correlate with how sick a person is, but I think of that as more of like the 102 versus 104. Like 104 isn't really more ill than the person with a fever of 102, but 106.5, like I said, it got my attention. Now, the kid got admitted and had labs pending and got some, I think, some IV antibiotics where we're trying to figure out if anything was really bad, wrong and everything came back fine.
Then later on I found out that a lot of the thermometers that we use, they actually calculate the interval of change, what we call the delta. So the thought was sometimes we get these spuriously high readings because it's calculating the amount of change over time and it kind of over extrapolate. So maybe if we had a mercury thermometer, like you can't find any of those now, maybe if we had a different source that was not digital, maybe we would have gotten a different temperature.
But anyway, that brings me to my talk for today, and that's just chatting with you guys about fever because I tell you, it's one of my favorite talks to get parents, when we get into the nuts and bolts of fever, because there's so many misconceptions out there and everybody's grandma has an antidote for fever, whether you're rubbing this on the kid or that, or setting them out in the snow, whatever. Everybody's grandmother has an answer for fever, but I want to give you my take on fever and when it's concerning, when it really isn't concerning.
So let's, first of all, identify the idea that not every fever is from infection. So that right there may have just blown your mind. You think fever, somebody sick with a bacteria or virus, but not all fevers are due to infections. So with that being said though, I want to initially talk about fever related to infection and then I will go over some of the things that cause fever that, really, there's no bacteria or virus involved. So one of the questions that I get asked all the time is: are fevers dangerous? I'm going to tell you that fevers due to infectious causes are almost never dangerous. So even the 104, 105 ... we'll take the 106 and 107s out of the picture for now ... but even the fevers that we feel like are really high, they're not really dangerous. Now, the underlying infection, that might be dangerous. So the bacteria in the blood, what we call bacteremia, or the meningitis, or the infected heart valve, that part is dangerous. So, yeah, people can die from whatever is causing fever. A lot of people these days have heard of the term sepsis, and that's basically where our immune system is overwhelmed with this infection. We're trying to fight it off and sometimes the chemicals that our body releases in order to fight off the infection, being harmful to us, and that's a different talk for a different day.
But, in general, if you have a fever related to an infection, the fever itself, isn't dangerous. Now, it makes you feel horrible. So I'm a big fan of treating those fevers, but in the overall scheme of things, that's not really the danger. So people do not have their brains fried because they had a fever of 104, even for several hours. So that might put your mind at ease. Doesn't mean that we don't need to investigate what the underlying causes is and figure out if that particular infection is dangerous, but it does give you some relief that when your kid's running a temperature of 102.5, his or her brain is not in any imminent danger.
So what about infection causes a fever? Well, that's really interesting. So basically we have these inflammatory mediators, our body identifies that there's a bacteria or a virus there that shouldn't be there, and our bodies are equipped to take on all of these insults. So one of the things that that we've learned over time is that we will reset our body's thermostats. So these inflammatory mediators called pyrogens ... yup, pyro, like the term fire or heat ... these pyrogens are released and they go to the hypothalamus in the brain, which is, amongst other things, it's controlling our body's thermostat. So I get sick. I'm ill. I've got pneumonia and then I have these pyrogens that are released as my body is trying to fight off this infection.
So my thermostat in my hypothalamus is saying 98.6 is no longer the temperature you should be at; you should be at 102. How does my body get to 102? Well, I start shaking and chilling. I get goosebumps. I'm freezing because my brain is saying our temperature's too low. It's no different than if you went out in the winter time and your body temperature was dropping. So how does your body compensate for that? You start shivering and generating heat. So when you get a fever, in the start of the fever, usually our bodies start shaking and chilling so that we get that temperature up and that temperature is going to stay there. Now, there's some thought that, that has developed because our bodies can survive at 102 or 103 or 104, and yet the bacteria or virus can't, or they can't reproduce as well at that higher temperature. So maybe it helps get rid of the infection, but nobody for the most part has really proven that we'd get better faster if we don't treat the fever. So, in general, I'm all about treating the fever because I think that that's what is making us feel so crummy. I know when I get sick, I might feel kind of bad and then when that fever spikes, I feel horrible. So at that point, Tylenol and ibuprofen become my best friend.
All right, so you or your child has a fever, you come see me as your doctor, when do I get concerned? Because there are still some times with fever, even from infection, that I'm going to get worried about what's going on. Again, it's more that I'm concerned about the underlying process, the infection that's causing the fever. But one of the things that will get me concerned is extremes of age. So when we're really tiny young, like let's say the first month of life, and we get a fever, that can be our only sign that something is going on, and it's hard to tell on a three-week old whether they have just a viral illness or whether they have something horrible and potentially life-threatening like meningitis. So when your kid gets brought to the Emergency Department at two weeks of age with a fever, he or she is going to get a lot of tests done. So some blood work, we're going to check the urine, make sure that that's not the source of infection, and probably are even going to do a spinal tap where we take a little needle in between the lower vertebra and we get some spinal fluid to make sure that this is not infection in the brain, in the meninges called meningitis that's causing infection because that's going to be really serious cause of infection and fever in a two or three week old.
The other side of it is, extremes of age, so the older folks. So as we get older, we don't always show the same signs and symptoms of a more serious infection. So as a person, is approaching the 80s, 90s, when I see them with a fever, I'm more concerned because I think that they are better set up for more serious infections. So I have to take a closer look at that. So age is going to be a factor for whether I'm concerned or not.
The second one is going to be just the overall appearance. So people who are really sick with something going on, they usually look really sick. So if you bring your school-aged child or your toddler to me and he or she has a temperature of 103, but they're dumpster diving in the trash can and they're running around and ask him to watch YouTube Kids on your phone, that's going to be a kid that, all right, right there, appearance, I'm not overly concern. So maybe this is a more benign cause of fever, a more benign infection.
So let's see what else would make me concerned. If you have something going on that has your immune system compromised. So by that, I mean that you are on like a chemotherapeutic agent, like you have cancer, or you have some immune disorder where you're not fighting infection like you normally would, or you're chronically on steroids, that's going to put you at risk for some different types of infection and more serious infections. So your immune status is going to play a role in that.
Then the other big area that I think would cause concern is just like some social issues or maybe back to immunity. Maybe if you didn't receive any vaccinations. Now I have to look at you in a different light and be concerned about some of those pathogens that I don't have to worry about in someone who is fully vaccinated. Other social issues like alcoholism, that lowers our ability to fight infection. Or, IV drug use, that's going to put you at risk for some very serious infections related to injecting and maybe getting skin bacteria in your bloodstream and those love to go and hang out on heart valves. So that's another thing that's going to play into my overall look at you and whether this fever is something that I need to be really concerned about or maybe we just need to treat the symptoms and see how you do.