You know that I love thermal polishes, so you'll imagine my reaction when I found the new Essence Thermo in Slovenia (so far it's an exclusive of Müller stores): happy dance buying two of them.
This is the first one I tried: It's hot stuff. This polish has a slightly dusty cyclamen shade, that becomes brigher and lighter when the temperature rises; it's quite pigmented and opaque after the first coat (I applied two for these swatches), once dry it remains also quite glossy. Application is easy, also because of the "old style" flat and not too wide brush.
Its reaction to temperature changes is quite subtle, but visible anyway (picture with warm hands indoors, tips are darker), I made a couple experiments with water to show the difference between cold and warm hands.
In conclusion, I think that besides the thermal effect (that won't last forever, read note at the bottom of the post), it's a pretty polish; not that original in terms of color, but easy to wear (and apply).
Technical note on thermal polishes: color change won't happen forever (some retailers declare a "one year shelf life" for them). Proper storage is important to make them last as long as possible (eventually the darker color might prevail). It's better to avoid UV exposure and high temperature (don't leave them under the Summer sun in your car, for instance), so I'd recommend keeping them in a cool place.