Lecture 3 - Grilled and Chilled
Humans live in extraordinary places - from the middle of the Sahara desert to the frozen wastes of Alaska. Take a snake to the North Pole, and it will stop moving in minutes. Take a cat to the desert and it can be dead in hours. So how can humans survive such extremes? And could you?
We’ve learned how the body burns fuel using oxygen and creates an ‘energy currency’. Here, we’ll learn how this creates heat. We’ll find out that some of the ‘work’ done when the energy currency is spent can keep you warm. We’ll discover whether shivering really works, whether a ‘hot meal’ really makes a difference and whether mothers are right when they say that you should ‘wear a hat on a cold day’. We’ll also find where blood is diverted when it gets cold.
But what about when it is too hot? Where does the blood go then? What is sweat and how does it work? And why do dogs pant, and humans not?
Finally, we’ll meet some survivors of the very coldest places in the world, and also the very hottest. What are the limits to survival? And how close did they get to finding out?