Do exist thermo lens for Nikon d5000?

Does anybody know whether there are thermo lens compatible for Nikon d5000? Is there any difference in thermo pictures made by a camera added thermo lens and a picture made by a thermocamera?

There's not much point in trying to turn a D5000 into a heat reading camera. Ideally you'd need a sensor of an entirely different design, and even the lenses require modification to correct for the difference in refraction caused by the change in the wave length of the electro magnetic waves being captured!

I don't believe there's such thing as a thermo lens. You would need a thermo body. It is the sensor which would need to capture the thermo image. Which lens you use should make little difference unless it has filters which specifically shield specific ranges, like a UV filter.

IR thermal cameras operate at a completely different wavelength than near IR. A standard consumer camera can't detect far-IR.

Suitable lenses for thermal IR work are commonly made of germanium or silicon. If you want a thermal camera, Fluke and FLIR make cheapo ($2500) thermal cameras. I prefer Fluke since they have a unit that allows you to focus to close distances.