Crisco Mitten

This activity was used to show students the value of fat as an insulator. They should be able to understand how bears and other Arctic animals are able to keep warm in cold weather whether they hibernate or not. Each student will have a turn putting his/her hands in the ice water. They will each put on the "blubber mitten" on one hand as protection, the other hand will go bare into the ice water. It will not take long for students to experience the benefits of fat as insulation firsthand!

First, you will need to get a quart-size baggie and a one gallon-size baggie. Put the quartz-size baggie over your hand and layer lard or vegetable shortening evenly on the bag. You will need warm water and soap to clean up after this messy step!

When you finish applying a good thick layer of lard to the smaller baggie, you will need to carefully put the gallon-size baggie over it. This way you won't get lard all over yourself! Carefully place a rubberband over the baggies to ensure that no water leaks into the blubber section.

Next, immerse the blubber mitten in the ice water. We used a 5 gallon bucket with snow in it. We added tap water and made sure the water temperature stayed around 30-32 degrees. That way the students knew what freezing temperature was all about! The mitten hand should remain much warmer than your bare hand. You should be able to keep the mitten hand in the water throughout this experiment.

Then, you will attempt to pick a penny from the bottom of the bucket each time. Continue to keep your mitten hand in the water at the same time. Notice the difference between the way your hands feel. The layer of fat keeps your mitten hand much warmer. However, you would find picking up pennies with this hand very difficult!

We put 10 pennies in the bucket. Students found that after 3 pennies, they noticed a significant difference in their ability to feel around the bucket for more pennies. Some students feel compelled to get all the pennies. We asked students to stop after they complained about pain or numbness during this experiment.

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