In this circuit a temperature sensor can be embedded in things like gloves and boots to sense when temperature is running too high or low. This version uses headphones that play a tone when a threshold is reached.
Extension Idea
Replace the headphones with an led indicator.
This tutorials walks you through how to create LED light strips that can be integrated into wearable projects.
Extension Idea
This technique is very common in adding light to wearable dresses and cosplay outfits.
This wearable tech project involves programming button controlled turn signals into a boking hoodie.
Extension Idea
Remove the Adafruit Lilpad and replace it with more basic circuits.