Detecting temperature changes has never been easier. The MCP9700 is a small thermistor type temperature sensor. This sensor will output 0.5V at 0 degrees C, 0.75V at 25 C, and 10mV per degree C. Doing an analog to digital conversion on the signal line will allow you to establish the local ambient temperature. Detect physical touch based on body heat and ambient conditions with this small sensor.
LilyPad is a wearable e-textile technology developed by Leah Buechley and cooperatively designed by Leah and SparkFun. Each LilyPad was creatively designed to have large connecting pads to allow them to be sewn into clothing. Various input, output, power, and sensor boards are available. They're even washable!