I finally got around to taking some measurements with my RayTek IR (essentially same tool as the Fluke), and thought you all might be interested. It's good to remember than when an object becomes hot to the touch, differences of even a few degrees may be be noticeable. And of course each person's response to heat varies, often substantially. Also, the nature of some surfaces makes measurements oscillate, hence some are averages of multiple readings and potentially +/- a few degrees. Readings the same whether a fresh load or ABV in the bowl. Ambient 75F. All are in Fahrenheit. The bowls were half loaded. So . . .
Set on noon at 15 minutes:
Bottom casing, ~105. Top casing, ~110. Screws, ~2 higher. Joint OD, ~180. ELB top cap, ~150. ELB ID, ~150. Herb, ~135. Bottom of ELB, ~130.
Set on noon at 60+ minutes (max temp):
Bottom casing, ~115. Top casing, ~120. Screws, ~2 higher. Joint OD, ~200. ELB top cap, ~150. ELB ID, ~160. Herb, ~140. Bottom of ELB, ~130.
Consistent with MacRadish's readings is my top screw reading of ~122, and the left side being a few degrees hotter than the right. The joint, ELB, and herb measurements are interesting. The heat moves up the glass path getting the joint pretty hot. But the bottom & top of the ELB are much cooler and remain so, and 30-40 degrees dissipate between the joint and the interior of the ELB, accounting for the relatively low temp of the herb itself. I took a lot of measurements of the herb, at rest, stirring, removing, and the readings were consistently in the 130-140 range; this appears to be the approximate interior ELB temp. I have occasionally detected a slight passing aroma a few minutes after inserting a fresh ELB, which dissipates fairly soon; given the low interior ELB and herb temps, I presume this is from evaporation of plant moisture.