What is a Heatmap
Heatmap shows Points of Interest in a color-scale. Places that are RED are more interesting for Tester (tester was looking there for a longer time than other points), BLUE spots are less attractive (but still - got tester's attention)
Heatmaps are great to show combined results from all tests. To see single test results, you should also check Viewmaps.
Heatmap representation of POI