Heat vision goggles, more commonly known as thermal-imaging devices, are commonly used by the military to perform various tasks and operations. The most common type of thermal-imaging device is night-vision goggles. Heat is detected by thermal night-vision goggles. Different heat sources such as people and objects give off varying degrees of heat, which allow the goggle wearer to determine whether the heat source is a person or an object. You can build your own pair of low-cost thermal-imaging goggles for educational and recreational use with materials found at most craft and electronic stores.
Remove the lenses of the welding goggles. Discard each green lens, keeping only the clear lenses. Trace the outline of the lenses twice on the red and blue theatrical gel sheets to have four outlines in total.
Use a utility knife to cut the four lens shapes from the gel sheets.
Apply a small amount of glue around the outer edge of a blue gel lens shape. Affix the blue gel lens shape to one of the clear welding-goggle lenses. Affix the remaining blue gel lens shape in the same way to the other clear lens.
Glue one red lens on top of each blue gel lens by applying a small amount of glue around the outer edge of each red lens.
Allow enough time for the glue to dry. Re-insert the lenses into the welding goggles.
Glue four infrared LED lights on the right side of the welding goggles. The first LED on the front of the goggles should be positioned so the positive lead of the LED is toward the front of the goggles. Glue the other three LEDs in the same fashion. This will allow the last LED glued to the right side of the goggles to have its negative lead toward the back of the goggles. Use the same arrangement when gluing the remaining four LED lights to the left side of the goggles.
Solder the positive lead of each LED to the negative lead of the LED light above it. Solder the connections on both sides of the goggles so only the first LED's positive lead and last LED's negative lead on both sides of the goggles are free.
Cut four small pieces of wire each two inches in length. Strip the insulation from both ends of each wire.
Solder the end of one wire to the free positive lead of the first LED on the right side of the goggles. Attach the free end of this wire to the negative side of a button cell battery. Glue the battery to the right side of the goggles. Solder one end of the second wire to the free negative lead of the last LED on the right side. Repeat this procedure on the left-side LEDs.
Power the LEDs on by taping the ends of the free wires to the positive pole of each battery on the left and right side. Wear the goggles in a room in complete darkness or outdoors at night to see the different heat levels emitted by people and objects. Various degrees of heat will produce different bright colours in the goggle lenses. Turn off the LED lights by removing the tape securing the wires to the batteries.
Add more LED lights to each side of the goggles if your image is very indistinct.
Always use caution when soldering materials and working with electrical components. Wear rubber gloves and take safety precautions to avoid potential hazards.