Are you referring to the UEFI shell environment? This environment is an extension of the BIOS and, in this environment, the processor is operating with all power management features disabled. This being the case, readings are going to be higher (and so are temperatures)...
Indeed, in the UEFI it shows ~1600uV.
In the Intel extreme tuning utility, it shows ~1500-1700uV, this seems quite high for a modern Intel CPU.
I'm worried this may affect the life of the CPU.
I wouldn't be. The processor decides what voltage it wants for its input.
The voltage changes automatically according to the system requirements as N.Scott.Pearson mentioned. Now, it is a good idea to reset BIOS settings to default and check the voltages. Get into BIOS, press F9, say Yes; press F10 and say Yes.