error inside Serial.<init>()

Using Arduino Interfacing w/ Software on the Computer
3

In the history of the universe, there has been more than one error. You are not getting "the error". You are getting an error, but you haven't told us that there error is.

You make me laugh most of the times... XD

Your code.

while (commPort.available() > 0)
{
tempC = commPort.read();
// and a million things here inside the while loop?
}

//maybe better

if (commPort.available() > 0)
{
tempC = commPort.read();
commPort.clear(); //let's clear the Port after reading the value.
}

or

while(commPort.available()<1)
{}
tempC = commPort.read();
commPort.clear();

This is probably not the source of your error; which by the way like Paul mentioned we don't know what it is. Maybe just another way to write the code.