I have experimented with this liquid crystal material and found sheets of Edmund Optics liquid crystal thermally sensitive sheets.
The sheets of liquid crystal material are offered in different temperature ranges to suit a particular task. Those temperature ranges are relatively small.
My findings were that the liquid crystal coating and liquid crystal sheets were too insensitive for use as a practical "thermal camera screen". Where the temperature sensitive sheets did offer some use was when laid over a PCB that offered a relatively uniform component height to the liquid crystal sheet. The hot components on the PCB quickly revealed themselves. The same can often be achieved by spraying a PCB with IPA or coating it with one of those Rosin Flux atomizers (I don't like either method though!)
So in precis, Liquid Crystal thermal detection does work, but is very limited in performance. It is not a cheap material and a lens would be needed. Your money would be far better spent on a budget thermal camera. They have never before offered such excellent value for money. Even a simple 80x60 pixel thermal camera would be better than the Liquid Crystal based "thermal camera". Dare I say, a MLX90640 32x24 pixel camera would be more useful in terms of thermal sensitivity and temperature measurement !
Regarding improving performance...
Cooling the liquid crystal film works against sensitivity as the film reacts in a certain range of temperature and cooling it pushes the film further away from where it shows change. It does not improve the thermal sensitivity in any way.
Making a more efficient "thermal collector" on the front face of the film would improve performance but thermal mass is your enemy so the film and any coating must be kept as thin as possible. The poor thermal sensitivity of the liquid crystal material will outweigh most/all improvements that could be used though.
This film is so insensitive that in a camera application, being used as the detector, you need high energy scenes. Take a look at the Planck's Law to see what this means in everyday life.
Fraser