100C / 212F is the temperature water boils at. You’re going to need at least twice that to combust something thin and dry, like paper. The wave soldering used in assembly of these components exposes them to temperatures exceeding 250C / 480F.

Silicon degradation takes place at sustained temperatures in excess of 120C.

There are plenty of notebooks that, by design, can boost the CPU up against its thermal limit (usually 95C or 100C) so as not to leave potential performance on the table.

On the topic of the article, operating temperatures of components like the CPU and general cooling of the system are wholly irrelevant.

The issue is that the 12VHPWR specification does not include the means to balance electrical load across the 6 VCC wires that carry power. Electrical current follows the path of least resistance - if that happens to be one wire over the others it may overheat, melt that wire’s insulator, melt the adjacent wire’s insulator, and eventually melt an adjacent ground wire’s insulator. VCC comes into contact with GND, a ton of current gets dumped into the shorted circuit, and there is a chance of a combustion event in the milliseconds before the PSU’s Over Current / Short Circuit Protection measures can kick in and cut power.

EDIT: Hadn’t read the article yet. It seems that this particular case involved a failure on the FBVDDQ (VRAM) line, not the 12VHPWR connector. The facts that this happened to a 5090 in an Alienware system are largely irrelevant, the most probable point of failure is a power stage or MOSFET which can and do fail in any laptop or graphics card.

I say largely irrelevant because the 5090 does have a TON of VRAM, it is possible that Inno3D cheaped out on a power stage / FET that is not up to the current demands of that much memory. If that were the case, though, I would expect to be seeing / hearing about widespread issues with this particular card in GPU repair communities.