It doesn't until you allow it to hit an object (in this case paper)
|Comparison of Atmospheric Transmission Germanium Lens response and quoted FLIR camera response|
How good is bubble wrap (packing material with 0.5cm air bubbles trapped between plastic)
|Single and double layers over hand. The spot temperature has had the emissivity adjusted so don't believe the temperature!|
Using the software's ability to calculate emissivity from the displayed temperature and the known hand temperature (approx 37°C with emissivity 0.92) gives the following results:
1 layer of bubblewrap requires an emissivity of 0.70 to correct the hand temperature to 37°C
2 layers of bubblewrap requires an emissivity of 0.69 to correct the hand temperature to 37°C
4 layers of bubblewrap requires an emissivity of 0.58 to correct the hand temperature to 37°C
8 layers of bubblewrap requires an emissivity of 0.55 to correct the hand temperature to 37°C
Compare this to 2 layers of cling film (saran wrap/ldpe) here
2 layers of ldpe are equivalent to 4 layers of bubble wrap (8layers of plastic and some air)
So an IR window of 2 layers bubble wrap (bubbles interspersed) will be better at IR transmission and probably better at conduction prevention.
You need aluminised bubble wrap to prevent hypothermia - need to stop the loss of IR!!!!