In order to check the temperature, you are going to need a decent thermometer. There are plenty of standard ones around that get the job done. You could also use a weather app to check on the temperature in your area. The Leaf Thermometer paper gives you a more creative way to check weather information. It is a piece of paper that looks like a leaf but changes color with temperature. It shows you when the weather in your area is hot, cold or just in the middle. Seems pretty fun to use actually.