Just doesn’t make sense
Our temperature is higher
We should feel hot (IMO) 🤷♂️
Edit 1: With that why do we feel so weak and tired when sick/have a fever
In: 3288
Humans are the best animal at getting rid of heat, all we need to do is take off our clothes, animals with fur can’t do that. When you have a fever, that’s your body trying to make itself so hot that whatever is attacking you can’t survive. As you get a fever, if you felt hot, you would take steps to get cooler, like throwing off your blankets, or taking your shirt off. This would stop the fever, which isn’t what your body wants. By making you feel cold, you stay in bed with the blanket on you, making the fever more effective at doing its job.
Your body has an internal thermostat, kinda like a house thermostat.
If you were to suddenly turn your house thermostat up from 20 C to 25 C, the house would suddenly go “oh no, I’m colder than I should be. I need to warm up so I can reach 25 C.” And it pumps heat into the house.
That’s the same reason you feel cold when you have a fever. Your body is telling you you need to be at 38 C instead of 36 C, and it triggers the feeling of being colder than you should be. That prompts you to seek out heat to help warm you up.
The extra heat can help kill pathogens, but your body also struggles and breaks down if it’s too hot.
You don’t feel temperature. You can only feel heat transfer: you can feel losing heat and gaining heat. For example, when a breeze blows, or you stand in front of a fan, you feel cooler, but the temperature hasn’t actually changed! Rather, your body releases some heat and that heat stays close to your skin; when a wind blows away that warmer air near your skin, your body loses more heat to the air to recreate that layer. This is also how jackets and blankets work; they trap in the warm air your body heats up. And it’s also why metal tends to feel very hot or very cold. It isn’t hotter or colder than the environment, but metal transmits heat very, very well, so the heat transfer happens quickly, which is why you feel it so much.
Note that these processes aren’t *active* processes. Your body doesn’t *release* heat as some sort of activity. It’s just two items of different temperatures coming to thermal equilibrium, except that your body produces its own heat all the time to replace the lost heat.
When you have a fever, you are warmer, so you lose more heat to the air around you, and therefore you feel colder. If your fever is 101°F, your 69°F room feels like it’s 67°, which is a little on the cold side.
There are multiple different mechanisms at play here, because… the body is COMPLEX! lol. I’m gunna break it down physiologically
1) – An infection is caused by a pathogen (bacteria, virus, fungi, etc..) This pathogen is recognized by the immune system as foreign. Immune cells then are triggered, which causes a release of chemicals from those cells that will cause a physiological response (these chemicals can be cytokines, Interleukins, Interferons, etc..).
2) Some of these chemicals (specifically Interleukin- 1, Interleukin – 6, Interleukin -8, Interferon- Gamma) flow through your body and reach your brain.
3) Your body temperature is regulated by a “thermostat” in the brain ( specifically the hypothalamus, of which temperature regulation is just one of the functions). The chemicals released into the body due to infection will go to the hypothalamus and tell it to “raise the temp, we got bugs causing some shit somewhere. Cook em up”. This causes a rise in body temperature from its normal resting temp to a higher one, which we call a fever.
4) Along with this, we have a function of the human body to regulate how our blood vessels work. Blood vessels can constrict and can expand depending on how much blood is needed in a particular organ. Blood carries white blood cells, red blood cells, basically everything you need to live and fight off disease, and it is *warm (*and blood cools itself when it flows through the skin to allow heat to dissipate). In certain conditions, such as eating, blood vessels supplying the skin will constrict in order to ensure more blood is sent to the gut to provide energy for digestion of food. In an infection, blood vessels keep more blood around the “vital” organs (heart, brain, lungs, etc) because these organs are a necessity for the body to function. This further increases core body temperature.
5) So now you have blood concentrated in the core organs internally and chemicals causing your thermostat to raise the temperature. The difference between the temperature between the internal organs and outermost organs (skin) is greater. This difference is what causes the feeling of “cold” as sensory receptors on and around the skin and other outer organs send signals to the brain via a spinal cord nerve tract called the “spinothalamic tract” that the difference between the environment and internal temperatures is greater. Think about when you go from inside your house in winter versus in summer. In winter, the outside temperature is lower than your internal temperature, thus you feel “cold”. Where as in summer, the outside temperature can be greater than the inner temperature, so you feel hot.
This difference is what is the cause of shivering. Shivering is one of the body’s mechanisms to raise it’s temperature via muscle activity. As muscles work they use energy from glycogen and other substances derived from the food we eat. This energy usage is not 100% efficient, and the un-used energy is given off as heat (Newton’s law of thermodynamics). This is the body’s way of attempting to heat the outer organs, as the skeletal musculature is closely attached to the skin via the subcutaneous tissue and fascia and shivering lets heat to flow out to the outer portion. Think about it. When was the last time you felt cold and then felt your liver or spleen or pancreas shaking inside you trying to stay warm? they don’t.
6) Weakness and tiredness are also related to these mechanisms. When those chemicals (cytokines, Interleukins, interferons) are released, some of them cause weakness and tiredness as well. This has a very good purpose: when fighting an infection, the body wants you to use all your resources to overcome this infection as fast as possible. Weakness is there to ensure you do not do something dumb, like a boxing match or run a marathon, while fighting the infection. Body doesnt want to share resources for unnecessary activities. Tiredness is to promote sleep. During sleep, your body releases more chemicals (complement system, etc) to fight infection. basically your immune system is MORE active while you are asleep than when you’re awake. Basically the body wants you to be in bed and asleep so it doesn’t have to divert energy towards frivolous junk activities while it is busy slaughtering foreign pathogens.
You don’t feel temperature itself so much as you feel change in temperature.
You feel cold in cold weather because the air is constantly sucking your body heat out of your relatively hot body. In weather around 75 F° or so (I don’t remember the actual temperature), the heat you’re losing is the same as the heat you’re generating, so you barely feel temperature at all.
When you have a fever, however, your body is much hotter. This means you have more heat to dump into the surrounding air, so you’ll feel colder than you normally would in the same air.
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