OK
TN42 on highest
28°C outside no wind
After 6m22s the part with switch and driver is hot
I still can touch it but not comfortable.
The tube gets warmer and the head too but slower then the tube
10m49s
Switch driver part is hot
Uncomfortable hot
Head lags behind
Battery tube hot but less then the hottest parts at 6.22
13m40s
I stop for the hottest parts are not nice to hold and I don’t want to heat it up too much
Ah what the heck ok after a minute cool down back to highest
Two minutes in, again driver and switch area not burning hot but too hot to comfortable touch
Placed it on a bench so no heat can escape via my hand
4m30s head is hot, tube is hot. Only driver/switch area feels burning hit but I can keep my hands on it without actually burning so it is between 50°C and 55°C
5m58s
Driver/switch area seems stable, head and tube still rising. (So we are ~20 minutes in on freshly charged Panasonic protected 3400 cells.
8m40s
The tube and head feel like when I stopped the first time.
After a couple of seconds I can’t hold the driver/switch area, it still rises in temp.
10m42s
Tube can be held without tendency to grip with one finger and switch fingers to give the heat no chance of giving a burning sensation.
Head, no more then 4 seconds in firm grip, gotta let go then, max 2 seconds for driver/switch parts
14m30s
Tube is getting too hot to firmly grip
No equilibrium
Almost half an hour in
Was I walking a little breeze would have cooled it, was it cooler or was there a little wind, that would have helped
Would I have held it, my hand could have taken away heat.
Turning off at 16m30s
Cells feel warm, lol tricky to unscrew the tube
Carrier is warmer
So half an hour in not ideal situation for cooling
Yes the GT should do better but we can up the default thermal stepdown for it for sure 
Five minutes later, all can be touched normally but is still warm to hot
Wow I am happy with the deep fins at the hottest parts of the GT!
EDIT voltage cells 3.81
walked with it on med for a few minutes too
starting voltage 4.19
pretty decent I think
.
!