The following sensors have been ordered and will be used for development.  They each have their own way of detecting conditions that may indicate Peril.

• Temperature sensor - sudden shifts of temperature up or down may indicate Peril
  
• Pulse sensor - a rise in pulse rate may indicate stress, therefore Peril
• Ambient Light sensor - sudden shifts in light levels (sudden darkness, sudden light) may precede Peril
• Sound Detector sensor - sudden loud noises or a sudden sound when there was previously silence may indicate Peril
• (TBD) Galvanic Skin Response - can be built from workbench supplies if needed.  Skin conductivity increases when sweat glands activate, due to stress.  Good indicator of actual or subconscious Peril.
• Accelerometer - to detect sudden movements; sudden movement on the wearer's part is a pretty good indication of Peril.  (Added 2014-04-07)