On a cold day, sometimes people will say "I'm freezing!," even though they aren't actually frozen like ice. But there is a very special animal that can say "I'm freezing" and mean it: wood frogs! Join Jessi and Squeaks to learn about the chilling way these frogs survive the winter! Science and Engineering Practices: Asking Questions and Defining Problems Disciplinary Core Ideas: PS1.A: Structure and Properties of Matter - Different kinds of matter exist and many of them can be either solid or liquid, depending on temperature. Matter can be described and classified by its observable properties. (2-PS1-1). PS1.B: Chemical Reactions - Heating or cooling a substance may cause changes that can be observed. Sometimes these changes are reversible, and sometimes they are not (2-PS1-4). Performance Expectations: 2-PS1-1. Plan and conduct an investigation to describe and classify different kinds of materials by their observable properties. 2-PS1-4. Construct an argument with evidence that some changes caused by heating or cooling can be reversed and some cannot.