Why Coats Keep Us Warm

Children will explore properties of insulation.


Lesson Objective

Children will explore properties of insulation as they experiment with covering bottles of water with different materials.


What You'll Need

  • Empty, identical plastic bottles with lids – 3
  • Hot (not boiling) water – enough to fill each bottle
  • Funnel
  • Newspaper
  • Winter scarf
  • Rubber bands
  • Thermometers – 3
  • Chart paper
  • Marker

What To Do

  1. Have the children bring their coats with them to the circle, and have them spend some time examining the coats.
  2. Ask the children what they may notice about their coats and why they wear coats (see Guiding Student Inquiry).
  3. Explain that winter coats insulate the body to keep us warm (see Vocabulary). Return the coats to their hooks.
  4. Tell the children they will be using bottles of hot water to experiment with insulation (keeping heat in).
  5. Using the funnel, fill each of the bottles with hot water and then cap them and dry the outsides.
  6. Allow the children to feel the outside of the bottles and tell about how they feel.
  7. Tape a thermometer to the outside of each bottle. Record the temperature on the chart paper.
  8. Wrap one bottle with newspaper, and secure it with rubber bands.
  9. Wrap another bottle with the winter scarf, and secure it with rubber bands.
  10. The third bottle will not have any covering.
  11. Have the children predict which bottle will stay warmer and write their predictions on chart paper.
  12. Place bottles out of the way for at least 30 minutes.
  13. After at least 30 minutes have passed, allow children to feel the bottles.
  14. Check the temperature of the bottles on each thermometer, and record the temperature on chart paper.
  15. Check the chart to confirm or revise predictions.

Guiding Student Inquiry

  • Explain why you wore a coat to school.
  • Describe your coat.
  • Tell me what it is about your coat that you think keeps you warm.
  • Describe how the bottles of hot water feel.
  • Tell me which bottle you think will not stay as warm.
  • Describe how the bottles of water feel (after at least a half hour).
  • Explain why you think that bottle did not stay as warm as the other two.

Explore, Extend & Integrate

  • Continue checking the bottles every half hour. Discuss why one bottle did not stay as warm as the others.
  • Perform the experiment another day using different winter apparel such as mittens, sweaters, or hats. Try using other materials, such as any type of paper, cardboard, or fabric.
  • Go on an “insulation hunt” around the classroom. Look for insulation in lunch boxes and totes, thermoses, foam drink can holders, windows, doors, and water pipes.

Check for Children’s Understanding

  • Could children explain why they think their coats keep them warm?
  • Could children describe the bottles as warm to the touch?
  • Could children make predictions?
  • Could children describe the bottles, after at least a half hour, as not as warm as before?
  • Could children explain that two of the bottles stayed warm because of their coverings?


Did You Know?

In colder weather, people usually wear coats when going outside. Coats keep us warm because of the material of the coat. Our body supplies the heat, and the material helps to trap body heat and keeps the heat from escaping into the air. This is what keeps us warm. Other items that can be worn to maintain warmth are hats, gloves or mittens, and scarves. Hats help keep in body heat by blocking the escape of body heat through the head. Scarves worn around the neck help to keep bare skin from exposure to cold temperatures. Gloves or mittens can protect hands from cold temperatures.

Many different materials can act as insulators to keep heat in. In our activity, the newspaper and the scarf were the insulators and helped to keep the warmth from the water bottle from escaping into the air. Newspapers are made up of layers. These layers keep the heat from escaping into the air and act as a shield. Scarfs are made of layers of fabric or yarn that also serve as a shield. It takes the heat longer to pass through the paper or the fabric than to pass through the air.

Vocabulary: Child-Friendly Definitions

  • coat – a piece of clothing worn over other clothes to keep warm.
  • insulation – something used to prevent loss of heat.
  • funnel – a tool shaped like a cone with a narrow tube at the small end.
  • thermometer – an instrument for measuring temperature.
  • warm – having some heat; not cold.
  • prediction – a statement saying ahead of time that something might happen or is expected to happen.

Lesson Tips

  • Use very warm, but not boiling, water for the experiment.
  • Place the bottles away from heaters or windows while conducting the experiment.


  • Bella’s Fall Coat by Lynn Plourde
  • The Jacket I Wear in the Snow by Shirley Neitzel
  • The Snowy Day by Ezra Jack Keats
  • Snow by P. D. Eastman and Roy McKie
  • Outside by Deirdre Gill

Home School Resources

Home educators: use these printable lesson PDFs to teach this lesson to your home schoolers. They're available in English and Spanish.

Home/School Connections

Las Conexiones a la Casa

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Content Provided By

Common Core State Standards Initiative – These lessons are aligned with the Common Core State Standards ("CCSS"). The CCSS provide a consistent, clear understanding of the concepts and skills children are expected to learn and guide teachers to provide their students with opportunities to gain these important skills and foundational knowledge [1]. Visit the CCSS