low cost low resolution bolometer arrays are easy to make if you have even a simple semiconductor fab (http://www.eee.metu.edu.tr/~tayfuna/papers/akin_c20_mems2001...)

The problem with anything built for military/medical/emergency service use, is that by the time you have ruggedized it, packaged it, setup service and support and got it approved by a dozen different agencies - well even a simple flashlight really does end up costing $100