Access violation of printing variable - c++

Question

I have the following problem where I will get an access violation exception when trying to print a variable, but only after a loop has run a specific number of times.
Specifically on the 211th iteration, the line:
cout << "Frame " << i << ", Recall: " << recall << ", Precision: " << precision << ", IoU: " << iou << endl;
Gives the error:
0xC0000005: Access violation reading location 0x3F09C003.
The weird thing is, this only occurs if I am printing a variable, and it always occurs at the 211th iteration. If I remove the print statement completely, or even just print a string, it works fine. But if I print any variable (i, recall, precision, etc.), it throws this exception. It will also throw the same exception if I remove the printing from the loop completely, and just have a single print statement outside of the loop. Any suggestions?
Code below:
template <typename T>
template <typename T2>
void Rect<T>::GetPerformance(const Rect<T2>& actual,
float &iou, float &precision, float &recall) const {
float numDetections = Area();
float numActual = actual.Area();
iou = Overlap(actual);
float numCorrect = iou *(actual.Area() + Area()) / (1 + iou);
precision = numCorrect / numDetections;
recall = numCorrect / numActual;
}
...
In Main
...
Mat frame;
Mat newFrame;
int i = 0;
float recall;
float precision;
float iou;
float avgRecall = 0;
float avgPrecision = 0;
float avgIoU = 0;
while (1)
{
iFrame = cvQueryFrame(capture);
if (!iFrame) break;
frame = iFrame;
FloatRect bb = carTracker.Track(frame);
bb.GetPerformance(gts[i], iou, precision, recall);
avgRecall += recall;
avgPrecision += precision;
avgIoU += iou;
cout << "Frame " << i << ", Recall: " << recall << ", Precision: " << precision << ", IoU: " << iou << endl;
i++;
}