The short version: It's inconsistent between shots, there's a delay before the heat dissipation begins (as opposed to testing grounds), and the heat display doesn't seem to scale right for small/big groups of weapons. Also, there seem to be values below 0% (even though 0% is the lowest displayed value).
The long version in Patch Feedback
As far as I know, this is the formula to determine the heat threshold for DHS:
heat threshold = (30 basic + 10 internal * 2.0 + n external * 1.4) * 1.2 elite efficiency
If you know something about the heat threshold other than or different to what I've mentioned (e.g. official statements), please let me know.
Also, it'd be great if you could share your observations including your ping. Best would be videos, can't make them myself because my FPS is too low in online matches (with MSI Afterburner screen capture).
What exactly happens to the heat display when you fire a high-heat weapon? What happens if you group-fire multiple?
Edited by Phaesphoros, 27 June 2013 - 02:37 PM.