That is a very good question. The answer is a resounding yes. But what your question didn't ask is "Which voltage will make my phone run cooler". And the answer can be rather shocking.
You can have two phones made at the same time that have opposite results using the same exact Low Voltage Kernel and Standard Voltage Kernel. On one phone the LV Kernel produces less heat and on the other the SV Kernel produces less heat. About know you are probably saying "Have you lost your mind, that shouldn't be possible".
The short answer is, in a perfect world where every OMAP3430 is exactly the same, I would agree the LV Kernel should always run cooler. But every OMAP3430 is different. On some, the LV Kernel simply doesn't have enough voltage to power the OMAP3430 properly. The result is usually seen in the form of sluggish behavior and extra heat. Where do those two side effects come from? The on board memory of the OMAP3430. It has a built in ECC (Error Correction Codes). This ECC sees that memory isn't being written to or read from properly and corrects itself when ever possible. So as you teeter on the edge of the proper voltage for the OMAP3430, it has to spend time correcting errors. Those corrections take power and CPU time. Which as stated earlier, are seen as sluggish behavior and a hotter phone.