Latest news with #bodytemperature
Daily Mail
11 hours ago
- Health
- Daily Mail
You're showering wrong! Scientist reveals why you should NEVER opt for cold water – even during the UK heatwave
There are two types of people in this world – those who enjoy cold showers and those who can think of nothing worse. Now, experts have revealed why you should never bathe in cold water, even during the UK heatwave. Adam Taylor, a Professor of Anatomy at Lancaster University, said a cold shower might actually not help us cool off at all. And it's all to do with how our blood vessels react to changes in temperature. 'Although diving into a cold bath or shower straight after being out in the heat might feel nice on your skin, it isn't doing what is needed to reduce the core temperature of the body,' Professor Taylor told The Conversation. Our body's optimal temperature is around 37°C, he explained. When our core gets too hot several mechanisms kick into place to help us cool down. One important response is our blood vessels dilating, to allow more blood to get closer to the relatively cooler surface of the skin. 'When exposed to cold [such as a cold shower] the blood vessels near the skin constrict, reducing the blood flow into these areas,' Professor Taylor said. 'So in the context of cooling the body down, jumping into a cold shower does the opposite of what needs to happen, as less blood is now flowing to the surface of the skin. 'This will hold the heat in and around your organs instead of getting rid of it. 'Basically, you're tricking your body that it doesn't need to cool down, but actually needs to conserve heat.' Sudden exposure to very cold temperatures could even trigger dangerous consequences for some people, he warned. Submerging yourself in water that is 15°C or under can trigger the cold shock response, which causes the blood vessels in the skin to constrict rapidly. This increases blood pressure and can be particularly dangerous for people with underlying heart conditions such as coronary artery disease. 'Thankfully, these events are rare,' he said, 'and probably won't happen if you're just taking a cold shower or bath in your home. 'But you might want to skip the cold plunge or avoid taking an ice bath on a hot day for this reason.' While cold showers aren't advised, hot showers also aren't the way forward on a warm day, he said. Water that is warmer than the body will transfer heat to the body, potentially increasing its core temperature. A tepid or lukewarm bath or shower, at 26-27°C, is most effective, he said. Another reason to skip a cold shower on a hot day is that it might not get you fully clean. Cold water has been shown to be less effective at removing and breaking down sebum and bacteria on the skin compared to warmer water. This means that body odour could persist, and trapped dirt within pores could lead to blackheads, whiteheads and acne. Warm or lukewarm water however, can help dissolve and loosen material in the pores. Eat spicy chilli, tikka masala, a Thai curry or soup to keep cool in the heatwave, say experts You might not think that a spicy chilli, tikka masla curry and soup would be the best things to eat to cool down during the heatwave. But it turns out that having a hot meal in the evening can actually help you stay cool by the sweat you perspire evaporating into the air and cooling the body. A chilli can also be helpful, with the capsaicin found in the food sending a signal to your brain that your body is overheated - so you will sweat more to cool down. Tucking into watermelon, turmeric and reducing the carbohydrates and protein in your diet are also good ways to beat the heat. Nutritionist Daniel O'Shaughnessy has teamed up with online delivery firm JustEat to compile a list of the best foods to eat or avoid in order to cool down. Traditionally seen as a winter dish, a bowl of soup in the evening as temperatures start to drop can actually help people stay cool, Mr O'Shaughnessy explained. He said: 'It will make you perspire more, but as the sweat evaporates, the energy is absorbed into the air, therefore cooling the body.' Mr O'Shaughnessy also believes a spicy chilli is a good choice, with the capsaicin found in the food sending a signal to your brain that your body is overheated. As a result, you will sweat more to cool down. The powerful anti-inflammatory effects of turmeric also make a tikka masala curry a good option in the heat. Curcumin, which is the active ingredient in the spice, helps promote good circulation, helping to speed up your blood flow and cool your body down. Mr O'Shaughnessy also named onions as a top pick, with the vegetable being used in Ayurvedic medicine, a traditional form of Indian medicine which is more than 3,000 years old, to treat heatstroke. Other heatwave choices recommended by the nutritionist include mint, thanks to its cooling sensation, as well as spinach, which contains the vitamins and minerals needed to help keep your blood pressure under control and keep you cool. Mr O'Shaughnessy said coconut milk, found in Thai green curry, has important nutrients to support hydration, prevent exhaustion and muscle aches in hot weather. And watermelon, which is high in water content, also contains citrulline, an amino acid which relaxes you and helps to dilate the blood vessels, meaning more blood can circulate around your body and cool you down. But there are some foods to avoid, with Mr O'Shaughnessy advising Britons to cut down on carbohydrate-rich foods, such as rice and wholegrains, and foods high in protein like chicken. He said: 'It may be harder to digest a high protein food in a heat wave. Meat is quite hard to digest and the digestion process creates heat (thermogenesis) and can make you feel hotter in yourself. 'Opting for plant-based dishes can be a good choice as less energy is needed to break vegetarian dishes down compared to meat.'
Yahoo
14 hours ago
- Health
- Yahoo
The dangerous consequences of taking a cold shower on a hot day
When the weather warms up, many of us use a nice cold shower to help us cool down. But while this might feel like relief, it might actually not be helping the body cool off at all. Our body's optimal temperature is around 37°C. This temperatures ensures our body systems can function properly. But when the core gets too hot the temperature regulating centre of the brain starts sending nervous signals out to the blood vessels and muscles in or near the skin – telling them to start activating their cooling mechanisms. If our core stays at high temperature for too long (around 39-40°C), this can lead to organ damage. So to ensure our temperature stays optimal, the body uses multiple techniques to cool itself down. For instance, the body radiates heat into the surrounding environment by electromagnetic (thermal) radiation. Approximately 60% of our body heat is lost this way. Sweating is another mechanism the body uses. Around 22% of our body heat is lost this way. But when the air temperature around us exceeds our body temperature, sweating becomes the dominant mechanism for reducing core temperature. Any remaining body heat is then lost through a mixture of convection into the air or liquid the body may be in contact with and conduction into solid objects that the body may be in contact with. To support these mechanisms, our blood vessels change diameter. The ones closest to the skin dilate (widen) to allow more blood into them so they can get close to the relatively cooler surface of the skin. The body then works to circulate the blood so that heat from inside the body can be moved to the periphery to cool off. Similarly on our skin, the hairs remain flat to allow air next to the body to cool and be replaced, helping to dissipate heat. Of course, when the weather gets really hot outside, these mechanisms just don't feel like they cut it. Although diving into a cold bath or shower straight after being out in the heat might feel nice on your skin, it isn't doing what is needed to reduce the core temperature of the body. It might also be risky for some people. When exposed to cold, the blood vessels near to the skin constrict – reducing the blood flow into these areas. So in the context of cooling the body down, jumping into a cold shower does the opposite of what needs to happen, as less blood is now flowing to the surface of the skin. This will hold the heat in and around your organs instead of getting rid of it. Basically, you're tricking your body that it doesn't need to cool down, but actually needs to conserve heat. And, depending on how cold your water is, sudden exposure could even trigger dangerous consequences for some people. Exposure to water that is 15°C can trigger the cold shock response. This causes the blood vessels in the skin (those in contact with the cold water) to constrict rapidly. This increases blood pressure as the heart is now pumping against increased resistance. This response can be particularly dangerous in people with underlying heart conditions, such as coronary artery disease. The cold shock response can also lead to an irregular heartbeat and even death when going from very hot to cold. Thankfully, these events are rare – and probably won't happen if you're just taking a cold shower or bath in your home. But you might want to skip the cold plunge or avoid taking an ice bath on a hot day for this reason. Hot showers are also a bad idea on a warm day. Although it's sometimes said that a hot shower helps the body cool down faster, this unfortunately isn't true. Water that is warmer than the body is going to transfer energy in the form of heat into the body. This again prevents the body getting rid of heat – potentially increasing its core temperature. On a hot day, a tepid or lukewarm bath or shower is the way to go, evidence suggests 26-27°C is most effective. This helps bring blood to the surface to cool, without being cold enough to cause the body to think it needs to conserve its heat. Another reason to skip a cold shower on a hot day is that it might not help you get clean. When we get hot, we sweat – and this sweat mixes with sebum, another skin product and the bacteria on our skin, which produces body odour. Cold water has been shown to be less effective at removing and breaking down sebum and other detritus on the skin, compared to warmer water, which means body odour will persist. Cold water also causes the skin to tighten. This might potentially trap sebum and dirt within the pores. This can lead to blackheads, whiteheads and acne. But warm or lukewarm water can help dissolve and loosen material in the pores. As you plan your escape and recovery from the heat this week, a lukewarm or cool shower or bath, rather than a cold shower, is a safer and more effective choice. This will allow your body to dissipate heat away from your core without harm. Equally, if you do feel the need to go cooler, do it gradually so you aren't shocking the body's automatic temperature regulation system into action. Turning the temperature down gradually if you want to go cold, or slowly placing a limb in at a time can help with this process. Adam Taylor is a Professor of Anatomy at Lancaster University. This article is republished from The Conversation under a Creative Commons license. Read the original article.
