are all a good deal warmer than usual - the temperature in my part of London has reached 37C this afternoon, so that's hardly surprising. Have you checked that the fan isn't running? It's easy enough to place your hand on the fan outlet at the back of the case and see. Then you can remove the case side and check the processor fan, and the one on the graphics chip if there is one (a fan).
If the PSU (Power Supply Unit) fan has stopped you'll certainly know about it, and if the CPU fan stops the processor will overheat very rapidly. Many motherboards shut the system down automatically in such circumstances.
Either way, if a fan has stopped you'll need to replace it before the machine is used again.