Ah - so you mean thermal radiation approximating to that of a black body. Light does not really come into it in all cases.
An incandescent bulb works by producing black body radiation (aka Light). An object will always produce light based on its temperature. That is how a infrared camera (aka night vision) can see a person in the dark.
https://kintronics.com/wp-content/uploads/2016/02/night-scene-IR.jpg
If you mean that polaritons can form without light, you are correct.
Abstract
We have investigated the similarities and difference between three well-known types of polaritons: phonon polariton, exciton polariton and surface plasmon polariton. For first two types (phonon polariton and exciton polariton) the interaction between photon and media can be expressed via a longitudinal-transversal splitting (LT-splitting), while for third type of polariton (surface plasmon polariton) via the boundary condition. Considering an analogy of these three types of polaritons, an effective LT-splitting was introduced for surface plasmon polariton.