Transcript:

So even in extremely cold weathers like this one, you can see ducks happily swimming in the lakes or in bodies of water. How is it that they are not losing heat to the water, which is freezing cold? It's an ingenious mechanism. This is how they do it.

So, the heart of the duck is pumping warm blood to the arteries. And as the artery is going down towards the leg, the veins that are carrying the blood back to the heart are flowing right next to the arteries. What is happening is the warm blood from the arteries is exchanging heat and is giving the heat to the veins that is carrying that blood back to the heart.

And as a result, when the blood goes to the extremity of the feet, it is almost at the same temperature as the water. In fact, it is exactly the same temperature as the water. So there is no net heat loss from the duck to the water, because there is no difference in temperature.

This way, the duck conserves all its energy, all its heat, and does not lose any of it to the water. It is an ingenious, ingenious design.