Why does a small increase in body temperature of 1degree put us into a fever state while we can adapt to higher temperatures on hotter days?


Why does a small increase in body temperature of 1degree put us into a fever state while we can adapt to higher temperatures on hotter days?

In: Biology

they are just two different things. in a fever, your body is purposely increasing its temperature as an immune system response to attempt to kill off germs that it has detected in your body. on hotter days, the heat it externally generated and your body works to maintain its normal core temp by sweating.

Ok, we have to clarify a few things first. Your body maintains constant temperature, because it’s important for your internals. Even if it’s a hotter day, your body still tries to more or less keep this proper temperature, that’s why it’s important to drink a lot, because we need it to cool ourselves. If your body isn’t able to cool efficiently enough – you won’t feel well and can even end up in hospital. The second thing – it’s not that an increase in body temperature makes you ill, it’s the other way round. If you contract a disease, your organism rises the internal temperature to mobilize the immune systems to fight, all effort goes into fighting a virus/bacteria and that’s why you can feel tired. Of course fever can be dangerous itself if it gets too high (more than 40 C).

>Why does a small increase in body temperature of 1degree put us into a fever state while we can adapt to higher temperatures on hotter days?

Your body maintains the same constant core temperature, regardless of the environmental temperatures. It will do anything to achieve this, cutting off blood circulation to extremities in cold environments and sweating profusely in warm environments.

Fever is your body trying to “cook” the germs, the same way we cook food to make it safe to eat. Sometimes though your body cranks the heat all the way up and burns itself along with the germs.

First, a one degree change in body temperature is not a fever. Most people’s core body temperature changes by one to two degrees over the course of the day.

Second, your body has mechanisms for maintaining a consistent core temperature as the outside temperature changes (e.g., shivering and sweating, or just slowing or speeding up your metabolism).

If the outside temperature is too hot or too cold for too long, your body will eventually be unable to maintain a normal core temperature, and you can die.

A fever state is a usually a reaction to infection wherein your body chooses to increase its core temp to be hostile to invading organisms. In fact, we have recently realized that the fever can be a helpful part of overcoming infections, and we don’t use tylenol as readily as we used to to bring down the fever.

Alternate question, how does raising the body’s temperature help develop the immune response?

Just because it’s a different termperature outside, doesn’t mean its different inside. Your inside temperature is relatively constant, no matter what the outside temperature is, thanks to tens of different mechanisms your body has to either increase temperature production, or decrease it, to compensate for outside temperature. So, if the outside temperature is too warm, the body will start sweating and reduce temperature production, among other things, all of which will make it not heat up. These compensatory mechanisms work both ways.

In addition to that, your outside is actually pretty-well insulated. You have clothes, that from closed packets of air, that act as an insulator from the outside environment.

Even when you’re naked, the air around your body is no the same as air 2 meters from it. The air closer to you will have temperature closer to your body, as opposed to air far away from you, which will have the temperature of an actual environment. This forms another layer of insulation – a layer which is broken when you move, or air moves – which is why a fan blowing air of 28 degrees will feel cooler than if you sit at 24 degrees, without air movement, since the fan will destroy that insulated layer, such that your 37 degree body will always be in contact with 28 degree air, as opposed to if the air didn’t move, and it would just be the same air, already warmed up by your body (which would mean your 37 degree body contact 37 degree air)

All of the above mechanisms ensure your inside temperature is constant, despite the flactuations in the environment.

When your body temperature rises, that’s a whole different process. And it’s destructive for many, many reasons, too long to write here.

So what you really should understand is, that despite fluctuations in outside temperature, mechanism are in place to ensure your body temperature stays the same. When you have a fever, your body temperature actually changes

It’s like no one in this sub has ever met a 5 year old.

Your body is very happy when it’s the right temperature. It’s so happy, that it has special powers to make it stay at that temperature all the time, even when it’s hot or cold outside. But sometimes, when there are germs invading, your body has some special knights who get called in to help beat the germs, but they like the heat so for them were willing to turn up the temperature to make them happy so they work harder until they defeat the bad guys and you’re healthy again.

Okay, so here is my ELI5:

Your body has a thermostat, just like your home does. It is pretty reliable, plus or minus a degree (actually less). Sometimes your body turns that thermostat up because it needs to fight off attackers.

But most of the time, it’s just chilling at about 36-37°C.

Just like your thermostat, it’s not just checking the temperature, it’s affecting other things.

In fact, your thermostat in your house is connected to two or three devices. Your body’s thermostat is connected to way more than that.

It can move blood towards or away from the core. Away from the core causes more heat to be given off. Towards the core conserves heat.

It can increase metabolism. Metabolism increases temperature. This is what shivering is. A way to increase metabolism through muscle movements that increases body temperature.

You also have some more active ways to increase temperature. You will often unknowingly do things like rub your hands together. You will close your arms around your body. You will move your feet.

There are some animals that even have “brown fat” which are little heaters throughout the fat that keep them warm even when their metabolism of their whole body is really, really low (like hibernation).

The body also has air conditioning. This is what sweat is. You can sweat a lot, and not realize it. Evaporating water is a great method of getting rid of heat, like AC. In fact, it kinda works in a very similar process.

Those are the main ones. I’m sure I’ve missed some.

The human body is really good at regulating it’s own temperature. Heart rate, panting, sweating, breathing, and some other mechanism allow the body to coold down if we’re in too hot of an environment, or warm up if we’re in too cold of one (within reason of course).

If your temperature is too hot it means something in your body is working properly to maintain that temperature, regardless of the external climate.

a small increase of 1 degree does not put us in a fever state. Rather, a fever state causes a small increase of 1 degree. Fever is a response, not a cause. Your body senses an attack, and mounts a defense accordingly. The increase in temperature activates that response.

Inside needs a constant temp of 98. Outside has ways of cooling off (sweat) or heating up (shivering) our outside doesn’t need a constant tempature but the inside does. Ofcourse we have our outside ways of cooling off and heating up. (Clothes, swimming etc…) why you go from hot to cold when you have a cold. Your body is trying regulate its tempature. Your body also raises its internal temp to fight off diseases.

Because your body has always the same temperatura aprox. unless if you have a problem.

(First of all, I’m not a doctor so I could be perfectly misstaken).

The sweat is part of the cooling system that most animals have and we’re not different (In fact is one of our best advantages in terms of evolution compared to other animals, that is why the humans are the absolute chad in terms of hunting). When the enviroment is hotter than our body, by the laws of thermodynamics, we would be hotter until we reach the ambient temperature but our *cooling system* allow us to keep that temperature unless is something that the system cant hold ( This is when we have a heat stroke). When we’re on a colder enviroment the blood system restrict how much blood we have on our limbs and concentrate on the mayor organs and the brain to protect them and also we “burn” more nutrients to try to keep the temperature.

The chemical reactions always happen between a certan level of temperature so when we have more temperature that what is normal for us (Hiperthermia) or less than that (Hipothermia) those reactions needed to keep us alive begging to have problems, they could stop at all or just being more and more slow.

This is what happen for example when we have feber, our body tries to kill whatever infect us by raising the temperature but the body also suffers the blow.

(What I dont know is why if the body strategy is to warm up the body we sweat so much, maybe someone that knows more than me about it, which is not very difficult, could answer that. I’m really curious about it)

we don’t adapt in that sense, our bodies have a cooling system to deal with external temp changes. internal temp changes are a built in response to illness. external temp extremes are more tolerable because it is not illness but just an environmental issue.

The “adapting to higher temperatures on hotter days” has a limit: wet bulb temperature >35C.

Our bodies use evaporative cooling to keep our internal temperature from climbing too high. Once evaporative cooling maxes out at 35C your internal temperature will climb to feverish and then deadly levels. The only remedy is to find or create a location that is cooler than 35C wbt.

Underground, dry the air, cool spring, HVAC, etc.

Something to keep in mind as extreme weather events become more frequent. A location at 35C 100% humidity will have a 100% mortality rate for anyone not able to find a cooler sheltering spot.

20 years ago, doctor’s aides used to freak out that my normal temp is 97.4. Now they don’t blink.

This simplest explanation of explicitly what you asked is actually philosophical, not scientific (in that, you really answered your own question):

We adapt to higher external temperatures through various means, like evaporative cooling from sweat.

If we have an increased internal temperature, it means we haven’t adapted in a manner to cool ourselves.

This has been brought to you by interpreting the semantics and ignoring the pragmatics.