Heat complaints get rejected at service desks more than almost anything else, for a straightforward reason: most of them describe normal behavior.
A thin laptop has very little room to move heat, so it’s designed to run hot and to spin its fan doing it. Report that as a defect and you’ll be told it’s within specification. The mirror-image mistake is just as common: a real fault dismissed as “they all do that.”
This guide is about where the line sits. There’s no way to read temperature from a browser, so there’s no tool on this page. What there is instead is what to look at in order to judge it.
What’s normal
Clear these first.
A CPU reaching the high nineties under load. Modern laptop processors target around 100 °C as a ceiling and reduce their own clock speed when they approach it. That behavior (thermal throttling) is protection working, not a failure. Seeing 95 °C during a game or a video export is not a problem.
A hot keyboard deck and base. The heat has to leave through something, and on a thin machine that something is the metal you’re touching. Uncomfortably warm is within range.
The fan ramping suddenly. Load arrives in steps and fans respond in steps. A fan spinning up “just from a browser tab” usually means something else started at the same moment.
A new laptop running hot for the first few days. File indexing, updates, and the manufacturer’s own first-run software all happen in that window. Don’t judge from the first few days. How to spot an early defect asks you to wait for the same reason.
Running hotter while charging. Charging itself generates heat.
What isn’t
These share one property: the heat doesn’t match the load.
Hot while doing nothing. Boot, leave it thirty minutes, and if it’s still hot with the fan running, look at what’s running before you look at the cooling. Open Task Manager (Ctrl+Shift+Esc) or Activity Monitor and read idle CPU usage. Around 5% is normal; a sustained 30% to 40% is a software problem, not a thermal one.
A fan that won’t come back down. Maximum speed for minutes after the load has gone suggests a sensor or fan-control fault.
Sudden shutdowns. Thermal shutdown is unambiguous. A healthy machine throttles instead of dying. Reaching the point of cutting power means the protection stack didn’t keep up.
Performance halving and staying there. Not a brief throttle, but permanently slow after a few minutes. That pattern points at cooling that isn’t doing its job.
One localised hot spot. Heat that concentrates in a small area rather than spreading can indicate poor heatsink contact.
Fan noise is about type, not volume
What kind of sound matters more than how loud it is.
Airflow. A rushing sound, normal even when loud. That’s the fan working.
Scraping. Metal on metal. A worn bearing, or blades contacting something. This is a fault.
Regular ticking or rattling. Repeating once per rotation. Debris in the fan, or a damaged blade.
Low-frequency droning. This may be the chassis rather than the fan. If pressing gently on the base changes the sound, it’s assembly.
No sound at all. A fan that never spins under load is either dead or not being driven. Silence isn’t automatically good news; hold your hand at the exhaust and check air is moving.
Common causes that aren’t defects
Eliminate these and most heat complaints resolve themselves.
Blocked intakes. Most laptops draw air from the base and sides. A bed, a duvet, or your lap seals that off completely. Move it to a hard flat surface and re-measure (ten degrees is a common difference).
Dust. After a year or two, compacted dust in the heatsink fins is normal. Blowing compressed air through the vents is within DIY range, but hold the fan still while you do it: spinning it beyond its rated speed with air pressure can damage it.
Background processes. Cloud sync, full antivirus scans, Windows Update, game launcher updates. All quietly expensive.
Power mode. A performance profile changes fan and temperature behavior entirely. Compare against balanced.
Browser tabs. Genuinely a major cause. Ad-heavy pages and autoplaying video across many tabs constitute a permanent background load.
Evidencing it
Heat is the easiest complaint to close as “could not reproduce,” so the record matters more here than elsewhere.
- Under which workload: not “after a while” but “twenty minutes into this game,” “ten minutes into a video call”
- Idle CPU usage. This is the core of the argument. Screenshot Task Manager showing low usage while the machine is hot
- Shutdowns: how many, and when. An unexpected power-off log is the strongest single piece of evidence
- Video of the fan, because sound type cannot be written down. Thirty seconds in a quiet room
- Whether it does it on a hard flat surface, the first thing you’ll be asked
- Whether you’ve cleaned the vents, and the machine’s age
The first two together turn “it’s hot for no reason” from an opinion into a measurement, and that difference decides most of these conversations.
For how to keep records in a form that still works weeks later, see the detailed check for a device you just bought.