Running hot, throttling, or the fans are constantly loud
What is actually too hot, what causes it, and what is safe to do yourself.
Safety level: caution · Time: about 30 minutes · Level: intermediate
Heat is the thing that quietly shortens a machine's life. Establish whether you have a real problem before taking anything apart.
Applies to
Desktops and laptops.
What is actually too hot
Modern processors are designed to run warm, and a number that looks alarming is often normal.
- Idle in the 30s or 40s °C is normal.
- Under sustained full load, 70–85 °C is normal for most desktop processors and common in laptops.
- Hitting around 95–100 °C and staying there means it is throttling — deliberately slowing itself to survive. That is the number that matters.
Throttling is the symptom to chase. It is why a machine feels fast for two minutes and then slow.
Steps
- Measure before acting. Install a monitoring tool and watch temperatures while doing whatever makes it loud. Note idle and load figures for both processor and graphics card. Guessing from fan noise leads to replacing the wrong thing.
- Check airflow around the machine. A desktop against a wall or in a closed cabinet recirculates its own hot air. A laptop on a bed or cushion has its intakes covered — that alone causes a large proportion of laptop overheating.
- Look at the dust. Power off, unplug, open it up. Dust packed into the fins of a cooler or a radiator acts as insulation and is the single most common cause of gradual overheating.
- Clean it properly. Use compressed air in short bursts, from outside toward the vents where possible. Hold each fan still while you do it — spinning a fan with compressed air can generate a voltage back into the board, and it is a genuine risk. Do not use a vacuum cleaner: they generate static.
- Check every fan actually spins on power-up. A seized fan is cheap to replace and expensive to ignore.
- Check the cooler is seated. A cooler knocked loose in transit, or one mounting screw not tightened, produces exactly this. It should not move at all when gently nudged.
- Review the fan curve in the BIOS. Constantly loud fans at idle are usually an aggressive curve, not a heat problem.
When new thermal paste is the answer
Paste dries out over years. If the machine is old, has been cleaned thoroughly, and still runs hot, repasting is the next step. On a desktop it is a reasonable job for a careful person. On a laptop it usually means near-total disassembly, and is not a first project.
Expected result
Load temperatures back in the normal band, and fans that rise under load and settle afterwards.
Stop and ask a technician if
- The battery is swollen — a bowed base, a proud trackpad, a laptop that rocks on a flat table. Do not press it, do not puncture it, do not keep charging it. Power off and bring it in.
- Anything smells burnt
- It shuts down by itself under load — that is a protective shutdown and continuing to run it is a bad idea
- It is a laptop needing paste or a fan replacement
- It is still throttling after a thorough clean
We clean and repaste routinely. Our charge and turnaround for a clean-and-repaste are 700₹ for desktop and 1250₹ for laptops.
Read this next
- It powers on but there is no display — If it now shuts down or will not display after running hot.
- Track a repair or service job — Booking a clean and repaste rather than doing it yourself.
Still stuck?
If anything here does not match what you are seeing, stop rather than force it. Contact us · Book a repair
Last reviewed 2026-08-30.