Over the last three days I've noticed some parts of the extruded
> door seals are hot to the touch. IR thermometer reads 9 deg above
> room temperature. Is this a known thing that I've just not
> noticed before?
Is it just when the fridge compressor is working? The back of the fridge will be hot so how is it vented?
For instance, my fridge is an under the counter type and is fitted between two kitchen cabinets with a gap of 0.7 cm each side and 1 cm * from the top of the fridge to the bottom of the work top. At times I can feel the warm air coming from the gaps, more so at the top.
Could the same be happening with your set-up with the seals retaining more heat than the surrounding metal from a warm airflow?
Can you actually feel the difference in temperature?
Is the IR thermometer actually just reading the temperature of the seals. It may have a larger capture angle for IR than misleading shown by a laser spot. Also the emissivity of the surface has to be considered. Some materials, or material finishes, can act as IR reflectors (IR mirrors) so what you may be measuring is something hot elsewhere being reflected from the surface of the seals. The usual advice where this is suspected is to put a piece of matt black tape on the item to be measured. What reflects IR may not reflect visible lights and visa versa.
*I had trouble finding a replacement fridge to fit an existing hole. Nearly all modern fridges seem to be externally larger than what could be found a couple of decades ago. Probably more insulation. The Liebherr larder fringe I now have is somewhat bigger than the old fridge and the only suitable one I found to fit without some kitchen remodelling hence the non-optimal ventilation. Two years since installation and no problems so far.