Clinical Skills: Thermoregulation

This clinical skills video focuses on thermoregulation, and how to treat conditions that can arise from patients becoming too hot (hyperthermia) or too cold (hypothermia), as well as the importance of early diagnosis and treatment.

Hi, everyone, and welcome to a Clinical Skills video. My name is Claire Blake and I'm a Registered Nurse lecturer.

So, today's topic is all about temperature, and I'm really excited to do this one because I, for the very first time, had a very high temperature and realized how awful it makes you feel to have such a high temperature, which I had no clue about before.

I've seen it in patients, but I didn't realize how physically sick it made you feel and how much it affects your life to have such a high temperature.

What Is Thermoregulation & How Does It Work?

So, the first thing I'm going to go over in this video is just a very, very short, brief, and very basic understanding of the anatomy and physiology behind thermoregulation. Thermoregulation in the body is your body's ability to control your temperature, basically.

But how does it do that? So, the hypothalamus in your brain is the first thing that you need to know about. This is like your control. This is your thermostat in your house. If you think about your controls in your house thermostat, that's your hypothalamus. It's going to keep running and running all day long, 24 hours a day, if it's a good functioning working hypothalamus, and it's going to just keep monitoring your temperature.

Your temperature should sit around 37 to 37.5 degrees Celsius, and it should just be regulated throughout the day. However, if there is a problem and your temperature started to rise or your temperature started to fall, your hypothalamus picks up these through the sensors in the body.

So, let's just say the hypothalamus is going. These sensors are triggering because it's saying, "Hang on, your temperature has now gone up to 38 degrees Celsius. We need to cool you down." What's going to be the effect of that?

What Happens If Temperature Is Too High?

If you are too hot, your hypothalamus will then send signals all the way to things like your sweat glands to produce sweat to make you sweat off this heat and cool you down.

It will also send signals to cause vasodilation, where your blood vessels under your skin will widen. This increases the blood flow to your skin. So, if you think about when your hot, sometimes you'll see your veins pop up on your hands. This is because the vessels are increasing and expanding, because this is where the heat is going to escape. So, it is trying to increase to get to the surface of the skin, to get that cool air to try and cool your body down, and this lets your body release heat through radiation.

And What Happens if It’s Too Low?

However, if your body temperature starts to drop and you need to warm up, your hypothalamus is going to send signals to different cells and different tissues and different muscles to help you increase your temperature.

So, it's going to do the opposite: vasoconstriction instead of dilation, and this constricts all of the blood vessels so that the blood vessels become narrower. And this just does the opposite, so it's decreasing the blood flow to the skin to keep your body warmer.

Your muscles will start shivering to try and generate heat. So, your hypothalamus is saying, "Everybody needs to go have a little jig, have a little party," and starts your body shivering to generate that heat in the body and increase temperature. And this is what they called thermogenesis.

There's also something called hormonal thermogenesis, and that's when your thyroid gland releases different hormones to increase your metabolism, which will then increase the energy that your body creates to hopefully increase heat.

Abnormally Low Or High Temperatures

Under normal circumstances, your body's quite good at regulating your temperature. However, there can be situations where you start to develop things like hypothermia, which is an abnormally low temperature for a long period of time, which could have serious consequences, even death, or hyperthermia, which is an abnormally high temperature that, again, could cause serious consequences and possibly death.

Symptoms & Stages Of Hypothermia

Some of the signs and symptoms of hypothermia could be things like shivering, slowed or laboured breathing, slurred speech, loss of coordination when you're trying to do things, a slow, weak pulse, confusion, memory loss, or even loss of consciousness.

There are five stages of hypothermia:

First, we've got the mild stage, where somebody might just experience shivering.

Then we've got the second stage. This is called the moderate stage, and this is where shivering may stop, and someone may start to lose consciousness.

The third stage is severe. This person has lost consciousness now, and it may be difficult to detect any vital signs such as the blood pressure, the pulse. Everything may have stopped.

The fourth stage is apparent death. So, this may be where you might start to do CPR of some sort. Those vital signs are no longer there.

And the final stage, as you may have guessed, is death. It's irreversible. There's no coming back from the hypothermia.

Recognizing it early, getting them treated early, is going to make a massive difference and prevent further damage being done.

Symptoms & Stages Of Hyperthermia

Then we have the opposite, hyperthermia, which is an abnormally high temperature. And like hypothermia, there are different stages. So, some signs and symptoms of this could be things like excessively sweating, shivering, feeling really unwell and sick and nauseous, dizziness, weakness, extreme thirst, and headaches.

One of the stages of hyperthermia could be heat fatigue. This is where high temperatures are causing you a lot of distress, discomfort, psychologically, physically, and this could just be due to extreme hot weather, for example. We've had some really hot weather recently, so some people might be experiencing this heat fatigue, heat exhaustion, or sunstroke symptoms.

Then you have something called heat syncope, also known as fainting. Your body has got so hot that you've passed out to try and relieve it, and this is what usually happens. Your body will start to shut itself down to try and relieve those symptoms because the less energy you use by walking, talking, moving around, the better. This is so that your body can try and repair itself, and that's the reason why your body starts to shut down sometimes.

Some people get heat cramps, and this is where your body is so hot, like when people over-exercise and really exert themselves, it will get different cramps because of the electrolyte imbalance in the body as a result of that heat. And to relieve this type of symptom, people need to drink a lot of cold fluids. Go to a cold place to cool down, stop exerting yourself too much if that's what you're doing, and just hopefully replenish those electrolytes that you've lost within that heat and that sweat.

People can get something like heat oedema, so that's where you get a fluid build-up in your hands, your ankles, your legs, your feet. Some people that have gone to maybe a hot country traveling or something like that, and you've been walking around all day in the heat, your feet tend to swell because that's the heat oedema setting in.

The Impact Of Illness On Thermoregulation

Like I explained at the very, very beginning, when I had COVID a couple of years ago, the one thing I really suffered with mainly was my temperature.

I couldn't control it. It was 38.5, so it was quite high. I was shivering. I felt freezing, so I automatically wanted to put something over me, but my temperature was saying that I was really, really hot.

I had ice packs, I was having cold baths, I was having cold showers, I was having paracetamol every four hours, and I felt so unwell I couldn't get out of bed. I felt exhausted, and that's when I knew there was a serious problem. But I just kept on top of it with the ice packs, the cold baths, the cold showers. I rotated between a few things and the paracetamol, and eventually, after about three days, it just settled.

I remember waking up on the fourth day; I woke up and I was like, "Oh, my temperature's gone." I knew instantly it had gone because I felt good as soon as I woke up, whereas the previous days, I felt so unwell, my eyes were really groggy. I felt groggy in myself, I felt nauseous. I knew I had a problem. My body was telling me that.

But on that fourth day, I woke up like there was nothing wrong with me. And I was like, "Oh, I'm better. That's really bizarre." And I checked my temperature, and it was normal. It was 37.4, and I was like, "That was really bizarre." So that just made me realize how really unwell a temperature can make you, and that wasn't nice. I wouldn't want anybody out there to experience that level of temperature. It's horrific.

How to Look After Yourself & Patients In High Temperatures

And this is why we need to look after ourselves and our patients because, like I said, it's been really extreme hot weather lately.

If you're working out there on placement, you've got your uniform on, which is a really thick material, it's not nice to work in. Usually in the Wards or community, it's really hot, it's really sweaty, you're on your feet all day. Make sure you're drinking plenty of fluids, getting a fan on you if there's fans in the building, if you're allowed fans.

Hopefully, you are working somewhere fancy with air conditioning, which I don't think many places do, but hopefully, there's a place where you can go and keep cool for a five, ten minute break and then recharge, and then off you go again.

And the same with the patients. Just make sure that you've got cool areas, you've got fans for patients, if it's allowed. I know infection control sometimes get a bit twitchy with fan use, but making sure all the windows are closed. People, first thing they want to do is open the windows in the heat, but actually that lets the heat in, so the best advice from the NHS is close all of the windows and curtains to keep it cool.

How to Look After Yourself & Patients In Low Temperatures

Of course, the opposite, is hypothermia. If someone's really, really cold, get them snug, get them heated up.

I know I've seen in the Ward placements; they have the ‘bear huggers’. They're called bear huggers, and it’s a little warm blanket-type thing with a little warm air that goes through it to keep people warm, especially after surgery, because after surgery, patients' temperature starts to drop a little bit. So, if you've got anything to keep your patients warm, keep them warm.

Is It Easier To Cool Down Or Warm Up?

And just in my own personal opinion, I don't know if there's any evidence behind this, but I think it's far easier... I don't want to offend anyone by saying this, so I'm really sorry. I think it's far easier to make someone warm than to cool them down, just in my own personal experience.

I would much rather it be winter, freezing cold, so I can layer up and can get my heater on. But if you've got a raging temperature, trying to cool down is really, really hard, I find.

And most patients I have seen personally have always got a temperature, and it's so hard to get them not to cover up because they're shivering, just to lay there, to have the fan on. They don't want the fan on because they physically feel cold, but they've got a raging temperature like I did. And get those antibiotics if they've got an infection, get the antibiotics into them, getting fluids into them, getting paracetamol into them to reduce that temperature down.

It can be really, really tricky, and it's really horrible to see in patients, so please look after all of your patients.

Recognise & Treat Early

So that's it from me. I hope this video's given you some awareness around temperature control in the body, hyperthermia, hypothermia, and different ways to handle that out there.

Just look for some of the signs and symptoms in your patients, so recognizing it early, getting them treated early, is going to make a massive difference and prevent further damage being done.

So that's it from me. I hope this video has helped in some way, but if you've experienced any of this and you want to discuss it, if you want to share any stories, maintaining confidentiality, give us a comment below and we'll get back to you.

Thanks, everyone. Have a great day.

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