toFixed() doesn't seem to work... why?

Code that works:

function onInit() {
  var cmd="";
  Serial1.setup(9600/*baud*/);
  Serial1.onData(function (e) {
    console.log("RX Data: " + e.data);
  });

  function getResTempValue(x) {
    var temp=0;
    var avgTemp=0;
    var tfixed=0;

    for (var i=0;i<x;i++)
    {
      var vOut = E.getAnalogVRef() * analogRead(A0); // if you attached VOUT to Ao
      var vZero = 0.4;
      var tCoeff =  19.5 / 1000;
      var tempinc = (vOut - vZero) / tCoeff;
      var tempinf = tempinc * (9 / 5) + 32;
      temp = temp + tempinf;
      console.log(temp);
      console.log(i);
    }
    temp = temp / x;
    tfixed = temp.toFixed(2);

    console.log("Temp: " + tfixed);
    return temp;
  }

  getResTempValue(10);
}

onInit();