My PC overheated ! 
I wonder why?

Take it outside, and blow it clean  using shop air or CAN-O-AIR (duster) sold in all good stores.  (never exceed 30 PSI pressure)
Then blow all heat sink and fans clean.  (and annual event here) always do this outdoor, never inside..
Lap tops waste   50-100watts power, is the range running fast App's, this heat is all mostly inside and must escape, if not allowed to breath and escape, and vent  the hot air, parts inside over heat and fail or self shut down.
Gaming desktops PCs can use 2 times that power levle and attendant that heat. ( Blowing up a $300 GPU is not fun nor smart?)  Heat is the number one killer of all electronics (dropping it #2?)
The ugly photos below are all neglect.

DT left; PSU right horrid
On can look here and in seconds knows what is wrong, and what to do... (clean it, get it clean by a PC pro,  or time to upgrade ?)

The PSU above right, is packed full and  below that and the the GPU and the CPU all rendered to overheated status, really what better torture can you do?

This is a Laptop heat pipe radiator,  some are 10x worse, heck most. See more below for worse.
This clogged up has the same effect as your cars radiator blocked , it overheats and for the same reason.
Below  is the CPU heatsink and fan assembly.  unscrewed and viewed, we can clean this outdoors with AIR and blast this to the great outdoors, never ever indoors.

Many things can overheat, even the HDD,and If you do not know how to solve those problems you fail as a tech.)  (my PCs all have a motor rpm (Fan) and all temperature monitor APP)
My desk top (ASUS) has BIOS monitors for all real tempeatures and fan speeds.  It can also be set up to warn you with beeps. (min. RPM thresholds and min. fan RPM threshold alarms)
The air flow must not be restricted
The Fans must  spin, at full speed (a laptop fan alway starts at turn on, (for safety of the LP) but then if the BIOS sees temps ok, it lowers the FAN RPM to keep noise down, but can be overriden easy with this APP.
The heat sinks must not be packed up like seen above.
The CPU thermal compound must not be failing ,same with GPU. if present and a fan there.
The i7 runs why hotter than the i5 processors.  The i7, I even need a cooling base ,fan plateform that helps greatly, blowing upward (sold it all good stores)

See this heat radiator, "A" below it must not be allowed to packup in lint.
See the FAN,at "B" ?  that fan must NOT be allowed to be packed in lint , in fact if you ignore the packup will stall the fan and the CPU will shut it all down !

Removing my keyboard or case top, helps greatly here to clean the fad and Radiator seen here, (a Toshiba and is horrible to undo hidden plastic snaps, I hate Toshibe LT) I'm upgrade this one to LED screen.

The same goes for all bottom vents below, if you run the PC on a blanket it will overheat, or if the vents on the bottom are all packed full of lint, it will overheat.  See those 6 vents, do not block them or allow them to pack in lint.

The HP 8540p/w series the key board comes off with 4 screws taking you to here, I then every year back blast the fan seen here to keep the radiator clear and clean.  (I blast it both ways vent on left then at fan port)

if you don't keep it clean like above, (annual)  you then  get to do this  horror.  taking the full top off, then remove 9 heat sink screws , clean it all on a bench the use this to put it back.
Some heatsinks , I discovered the HS compound turned to hard fractured glue, the cure is this.

Next up the Heat Pipe Radiator blues:
Below you can clearly see the heat pipe, radiator is packed full of lent , rendering it useless causing the CPU to overheat fast. Getting to here takes work,  including the heat sink at the Cpu detached.
real drama here!

Here is  HP GPU board, clean.
HP GPU card, fan and 3 caps that love to explode ,crack or leak acid. (from the bad cap era)

Do not forget case fans,  (on HP desktop) if dead?, the HDD can overheat, on some PC's (never mine) the PSU is the only case fan in the system (mine as 2 case plus PSU, and CPU and GPU fans)

Can o Air. duster

version 1.  7-25-2017