Leaf is a paper thermometer that shows the room temperature by changing its color. It is green when the temperature is between 68–77°F (20–25°C), brown when it’s cold, or it turns yellow when the temperature is above 77°F. Leaf has a small reusable adhesive seal. Design by Hideyuki Kumagai of T3 Design for +d.

Leaf Thermometer, Small, $1.25 – $9.90