Subtitles section Play video Print subtitles Ughh...Is it hot in here or is it just me? 00:00:08,800 --> 00:00:10,620 Hey everyone! Thanks for watching DNews I'm Julia. And I'm Trace Humans are warm blooded, so you would think that we would be warm all the time, but that's actually not what warm blooded means. There are those of us who are, well, cold all the time. But that doesn't mean we're cold blooded. Cold blooded animal's body temperatures are subject to the temperature of the room they're in, whether that's the forest, sitting in the sun, or hanging out in the cozy kitchen. On the other hand, warm blooded animals have the ability to internally regulate their body temperatures, independent of their environment. It's called being homeothermic, and it's common in mammals. Humans average around 98.6 degrees Fahrenheit, cats and dogs have around 101 or 102. Dolphins are around 95. Lions are over 102, but note that I said "average". Body temperatures can range, and in humans women are usually colder than men and older people are colder than younger. Temperature regulation starts in the brain and is controlled by hormones. The brain takes into account the body's core temperature and the temperature of the outer skin. Fatter people tend to feel warmer because their core organs are all toasty. Though their extremities are colder. While people with lower BMI's tend to feel colder because blood pumped through the extremities needs to be really warmed up when it gets back. Warming the blood is the major way we can regulate our internal temperatures. When thermoregulator cells in our skin detect a cold environment they constrict our capillaries and blood vessels in a process called vasoconstriction. This can cause the flow to slow as little as 0.02 liters per minute in the far-flung parts of the body, the highest can be 2-3 meters per minute. The lack of warm blood is what makes my hand and feet cold, and yours too. Yes, which of course has to do with the amount of body fat, but also has to do that women's bodies work harder to keep their core body temperatures up, in comparison to men. This leaves fewer energy resources to warm the extremities. Human biology dictates that men tend to have more muscle mass and women tend to have more fat. The working of muscle generates heat, while fat cells store it. Researchers at the University of Utah measured the temperatures of men and women's hands and found men's hands were 90 degrees on average, while women's were 87.2 And a study in The Lancet found the hormone estrogen is part of this temperature regulation system too, which is a whole other bag of cats. During the menstrual cycle, a woman's body can change as much as 1.8 degrees Fahrenheit, which is a huge difference when you're talking about the core temperature of a human. Age, diet, exercise and sleep will also effect body temperatures and the amount of warm blood getting to our extremities. People who are more active tend to have warmer hands and feet overall than those who don't. People who smoke have more vasoconstriction cooling the extremities. When you fall asleep women's body temperatures lower more rapidly than men's. Of course some of this is person to person dependent. My feet are frozen at night, but during the day I'm always hot. And it's not even just about being physically hot, it's also our perception of temperature which affects our feelings of whether we're hot. Right! If you're surrounded by people you are comfortable with you'll feel warmer. Also, a Canadian study found people who are lonely or feel isolated are more aware of a cold body temperature, while socially connected people tend to feel warmer. That's true. What about you guys, are you always hot? Are you always cold? Let us know down in the comments. Make sure you subscribe as well to DNews, so you can get more of this everyday! Also, check out this video over here about whether shivering could help you lose weight. Thanks for watching DNews, see you later, guys! See you next time!
B1 US temperature blooded body warm tend warmer Why Are Some People Always Cold? 46 3 哲維范 posted on 2018/02/12 More Share Save Report Video vocabulary