I thought that those with a deep insight into how laptops, tablets etc work might know the answer to this question.

I watched a drama earlier which revolved around someone hacking into a device and doing something to the process that regulates the battery. This involved cases of remote arson as it made the battery hotter and hotter until it set on fire, because the regulatory function had been impaired.

Is this purely fictional, or could something actually be done along these lines?

Fiction.

Yes, in theory, you could stop fans and keep everything running at full speed, but I doubt a PC would catch fire, let alone a tablet.

Thanks

The only potentially flammable device in laptops, tablets, and similar devices is the battery: the other components, ones which may be cooled by fans such as the CPU, GPU and power-supply will shutdown if a critical temperature is reached. This shutdown is outside the control of anything which can be adjusted in the BIOS or tampering with the firmware of those device, it is built into the chip or power-supply components in question.

As for the battery which is what you say they did in the drama, that in theory could be made to overheat, and catch fire if an attacker were able to modify the firmware controlling the charging circuitry in the device. Causing the battery to overcharge at maximum current could result in it exploding or briefly catching fire, though the damage would probably be limited to the device itself (destroyed) and the immediate surroundings (scorched desk or worktop).

Best advice is don't leave things on charge when you go to sleep, and if you must do so, ensure the device isn't sitting on or near something which could easily catch fire itself. The device's battery, even in a performance laptop PC which will have a far larger battery than any laptop, will not set fire to a room unless it is able to set fire to things close to it. This should be obvious, but never go to sleep with something charging under or close to your bed

The Motorola 6502 chip used to have a halt and catch fire sequence. A sequence of particular instructions caused it to go into an unstoppable loop and it would eventually get hot enough to destroy itself.

LOL - you'll be telling me next that the JMP instruction makes the computer leap in the air

maybe you took the HCF TV series too literally, or were thinking of this XKCD joke

Gawd I pretty much do that every night. Eek!

Sounds like a variation on the "Mission Impossible" introduction.