Of Sweating After Teh O Limau anas, and Thinking....

The other day I was teaching the chapter ‘Chemicals of Life’ in Biology. One of those ‘chemicals’ as we all know is water. And we discussed the importance of water and the various roles it has in cells and living organisms, one of which is for cooling. I wanted them to try and figure this concept of cooling out for themselves. So I said, “Whenever I go to Tok Wan for lunch (tok wan is a restaurant next to the school, not my grandfather’s house), I like to order teh O limau panas. And as I finish the drink, I start sweating. Why is that?” I asked them.

Students: Coz your body is hot?

Me: But why is my body hot?

Students: Because you drank something hot?

Me: I know but how did this happen? Why is it that when I drink something hot, my body becomes hot? And why when I drink something cold, I feel cold? What’s going on? 

Students: umm…. The heat has moved from the drink to your body.

Me: Yes, good. And when I drink something cold?

Students: ummm... (they were slightly stumped)

Me: So the heat has moved from where to where?

Students: The body to the drink…?? (they sounded unsure)

Me: Yes exactly! Heat moves from a place of high heat energy to a place of low energy. So back the hot drink. Why do I sweat then if my body becomes hot?

Students: Because the water is cold, so it can cool the body.

Me: The water is cold? No, that’s not the mechanism. Ok, the water cools the body but how?

Students: Ummm…. (they were stuck)

Me: Ok, when you sweat, what happens to the sweat?

Students: Falls to the ground…

Me: Well, that is if you sweat a lot. Let’s say you sweat just a bit, like you have some beads of sweat on your forehead. What happens after a while?

 

Students: It disappears….

Me: Disappears to where? Magically disappears?

Students: It evaporates.

Me: Yes, so what happens when the sweat evaporates?

Students: The water turns to gas.

Me: Ok, but how does it turn to gas?

Students: ….

Me: Use your knowledge of chemistry, what kind of process is evaporation, heat absorbing or heat releasing?

Students: Heat absorbing.

Me: Yes, correct, so? Where is the heat absorbed from?

Students: From the body….? (still lacking confidence in their answer)

 

Me: YES! That’s how your body cools itself….

Students: Ooooohhhh….. (they were awed by this ‘discovery’)

Me: See, you can come up with the answer yourselves, isn’t it?? You just need to think, with a bit of prompting from me…..

Some of them were beaming with delight after this exercise, perhaps pleased with their ability to come to the answer on their own with some effort, and with how science beautifully explains the phenomena around them. I reminded them that this is how the IGCSE exam expects them to think and come up with answers. And that the sciences are only divorced in the class, but intimately linked with one another in real life.

This is a new journey for me and the students, to help them exercise and use their thinking skills. Like muscles which cannot be used to lift heavy weights if it is not trained, the brain too will be crumbly and dull if it is not trained to think, unable to solve problems. It is a challenging journey, but an interesting one nonetheless. May Allah assist!