2004 XJR (X350) I have noticed that all of my metal interior door handles get hot to the point that they are uncomfortable, almost painful, to touch. This only occurs when car has been sitting out in the heat, and admittedly, it is July and August in North Texas, which means that temps are constantly above 100F / 38C. Once hot, the heat takes forever to dissipate.

I recently had paintless dent repair done, and I imagine that, to do this, they would’ve removed any insulation, if any, in the doors. They failed to put two door hinge pins back in and screwed up my sunroof, so failing to reinstall insulation is not outside the realm of possibility.

Then again, the car hails from country unused to this level of heat.

 

I have always found that to be the case with chromed metalwork that gets direct sunlight falling on it.

You naturally think the highly reflective surface would not allow the energy to penetrate, but in actuality I think it is like mirrors...you don't get 100% total reflection, some energy gets through.
In the handle's case that energy then encounters the reverse effect when energy tries to leave it, it has trouble escaping from the inside again due to reflection.
The reason why kettles and thermoses are highly polished metals, to reduce the infrared energy transfer.

I doubt the omission of any door insulation would allow that much heat to soak into the handles, this is likely just the cumulative gain of direct sunlight.
Try a test by draping some scrap material over the handle to block the sun and see if the handle remains a lot cooler.
If that works, then you are left with either fashioning some covers out of a more suitable material, or you may consider adding a tint to your allowable windows.

 

So, I did an experiment. I measured the ambient temperature, the temperature of the driver’s side door handle, which I covered with a heavy towel, and the passenger’s side door handle, which I left in covered to serve as my control. I took several measurements throughout the day, and at no point did the temperature of the passenger’s handle exceed the temperature of the driver’s door handle. It seems that the heat is radiated from the body panel.

I suppose the next step is to remove an interior door panel and see if there is insulation. I’ll check the repair manual, but I suspect there should be some as I have seen it in other cars.

Edit: I emailed the previous owner to see if he had this problem.

 

@PowdyrdWyg Two comments here:
1. what did you measured temperature with? Contactless IR thermometer it comthing that has contact temperature probe? Accuracy of both depends on technics, IR methode, please keep in mind that temperature measured not at the red point, but rather, integrates surrounding area, round spot around red point. The farther away from surface the greater the spot.
2. consider the fact that that sun shines in one direction, so radiated heat from sun will lit up one side, not both.

Also, I assume you left car for a day and did not use it.
There are a lot of assumptions here, not enough to come to conclusion. Sorry, man, measurements, metrology, is my thing!

 

Big K,
Sorry for the delay. Closing the loop. I did not drive the car, letting it sit in the sun. I used a contact thermometer and tested all four door handles, one of which was covered. There was no difference in temperature across the handles. It’s not a scientific test, but I think it rules out direct sunlight as the source of the heat. Radiation from the door is more likely.

At some point, I’ll pull off the door panel to see if there is any telltale butyl tape remnants where a vapor barrier (I used the generic “insulation” in the original post) used to be.

I appreciate your interest.