How Dangerous is Your Holiday – 3. Winter
Baby it’s cold outside, if you’re on a winter holiday. Here are three experiments you can do at home to explore some of the science of brrrrrrrr.
Dick and Dom investigate how we feel heat and cold, and how to stay warm in freezing temperatures.
1: How to make a blubber glove
Many animals that live in the cold are protected from the extreme temperature by a layer of fat called “blubber”. Find out for yourself what it’s like to be a polar bear by making a blubber glove … and then getting into freezing water.
You will need:
- Two freezer or sandwich bags, big enough to put your hand in easily
- Gaffer tape
- A bucket of cold water
- A bag of ice
- A timer
Put several large spoonfuls of lard into one of the freezer bags, and squash it out into an even layer. Now put your hand into the other (empty) bag, and place your bagged-up hand inside the lardy bag. Mmmm – lovely! Squash the lard around until it completely surrounds your hand, then carefully remove your hand. Fold the top of the inner bag around the outside of the other bag. Now seal it all around with gaffer tape so that no lard can escape, but you can still get your hand in.
Add the bag of ice to your bucket of water, to make sure it’s really, really cold. You are now ready to test out the power of blubber…
Using your own hands, or maybe you can persuade someone else to volunteer, use the timer to test how long you can keep your hands in the water. Hand 1 is naked, Hand 2 wearing the blubber glove. Remove your hand from the ice before it starts to become painful - do not hurt yourself!
What difference did you notice between the two hands? Did you feel the protective power of the blubber?
2: The hot and cold hands illusion
Don’t dry your hands yet because here’s another experiment, showing how you can fool your senses about how hot or cold your surroundings are.
You will need:
Three bowls filled with water - one hot, one very cold, and one room temperature.
Put one hand into the warm water and one into the very cold water, and leave them there for 30 seconds. Take your hands out of the water and immediately put them into the bowl filled with room temperature water. How warm does each hand feel now?
Both hands are in the same temperature water – but you’ll probably find that the hand that's been in the cold water now feels quite hot while the one that was in the warm water feels cold.
Your senses are relative, so when one of your hands goes from hot to medium water, it will feel much cooler than before. Meanwhile the hand that’s gone from cold to medium, will feel much warmer. If you try this experiment on a blindfolded volunteer, don’t tell them there’s only one medium temperature bowl. They’ll be astonished when you reveal both their hands are now in the same water.
3: How to warm yourself up, from the inside
Even in freezing temperatures, people stay warm if they’re active. This is because your body makes use of energy stored in the food you’ve eaten, and turns it into heat. You can experience this effect for yourself by standing outside in the cold for a few minutes ... then run about for two minutes and notice how much warmer you feel.