It will prevent objects from shedding heat through radiation, but it does not seem that it will in any way prevent them from shedding heat through conduction, c

It will prevent objects from shedding heat through radiation, but it does not seem that it will in any way prevent them from shedding heat through conduction, convection, or evaporation. If the film were on the outer layer of a garment, as long as the inner layers still allowed the soldier's sweat to evaporate they would still be able to keep cool.