It’s so Cold it’s Hot

It’s so Cold it’s Hot

Chilly and rainy days are synonymous with February around here recently, but that doesn’t mean you can’t have some fun indoors while experimenting with creating your own icy towers that give off heat! Create a frozen landscape that is warm to the touch, while exploring solutions and crystallization. Be sure to wash your hands after playing with the materials and have fun!


  • 1 liter vinegar
  • 4 tablespoons baking soda
  • Saucepan
  • Bowl
  • Shallow dish


  1. Pour the vinegar into the saucepan and add baking soda a little at a time, stirring between the additions of the baking soda. The baking soda must be added very slowly, or you’ll mimic a volcano the mixture will overflow!
  2. Now it’s time to boil the mixture – Be sure to ask an adult for help! Boiling the solution will concentrate it.
  3. Boil the solution for about an hour. You’ll know it’s ready when a crystal skin starts to form on the top. The mixture may discolor, but no worries!
  4. Remove the pan from the stove and pour the solution into a bowl. Cover it to prevent evaporation.
  5. Place in the refrigerator to chill and be careful not to jostle it.
  6. Scrape up a little of the sodium acetate powder that remains on the saucepan and place in the shallow dish.
  7. Remove the solution after about 45 minutes and pour it very slowly over the sodium acetate powder and see what happens.
  8. You should see towers grow in the pan. Touch it and it’ll be hot!

Hot Ice? How does that work?

When the sodium acetate solution is placed in the refrigerator, you’ve created a super cooled liquid, meaning it exists in liquid form below it’s normal melting point. Crystallization occurs when you pour the liquid over the powder and creates an exothermic reaction, which produces heat. Sodium acetate is sometimes used in hand-warmers since it produces this reaction! Try adding food coloring to the solution to see if you can create rainbow ice towers.