If, Else If, and Else statements are not refreshing

Projects Programming
2 
int tempF = sensors.getTempCByIndex(0);

Even if this works as written, it would try to read the temperature before you have requested that a temperature conversion start. After that, you never set tempF again.
Change it to just:

int tempF;

And change this:

 Serial.print(sensors.getTempCByIndex(0));

to this:

  tempF = sensors.getTempCByIndex(0);
  Serial.println(tempF);

Pete