Computer Running Hot? Here's What to Do About It

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title: "Computer Running Hot? Here's What to Do About It" description: "Overheating slows down your computer, causes crashes, and shortens hardware life. Here's how to check temperatures, find the cause, and fix it." date: "2026-05-15" keywords: ["computer running hot", "laptop overheating fix", "computer overheating", "cpu temperature too high"]

Computers slow themselves down when they get too hot. It's called thermal throttling and it's a self-protection mechanism. So if your laptop suddenly feels sluggish, gets hot to the touch, or the fan sounds like a jet engine, heat is likely involved.

Here's how to diagnose it and what to do.

Check Your Actual Temperatures First

Don't assume it's overheating because the chassis feels warm. Check the numbers.

On Windows: Download HWMonitor (free, from cpuid.com). It shows real-time temperatures for your CPU, GPU, and hard drives.

Normal ranges:

• CPU at idle: 30-50°C
• CPU under load (gaming, video editing): 70-85°C
• CPU critical temperature: above 95°C (will throttle and possibly shut down)

If you're hitting 90°C+ while just browsing the internet, you have a problem.

On Mac: Download iStatMenus (paid) or Stats (free, from GitHub). Look at CPU and GPU temperatures. Same general ranges apply.

Activity Monitor (built in, under Applications then Utilities) also shows which processes are consuming CPU, which helps identify what's generating the heat.

Fix 1: Clean Out the Vents

Dust is the most common cause of overheating, especially in laptops that are 2+ years old.

Dust accumulates inside the vents and on the fan blades, blocking airflow. The computer can't exhaust heat effectively and temperatures climb.

For laptops: Use compressed air (available at any office supply or electronics store). Hold the can upright and spray in short bursts into the vents, usually on the bottom or sides of the laptop. Do this outside or over a trash can.

Don't hold the can upside down. The liquid propellant can damage components.

For desktops: Remove the side panel (usually one or two thumbscrews) and spray compressed air through all fans and heatsinks. A desktop that's never been cleaned can accumulate serious dust buildup over a few years.

Fix 2: Check Your Surface

Laptops need airflow underneath them to breathe. If you're using it on a bed, couch, or your lap, the vents may be fully blocked.

Use a hard flat surface, or better, a laptop stand with a cooling pad. Cooling pads with built-in fans ($20-40) can drop temperatures by 5-15°C, which makes a real difference for sustained workloads.

Fix 3: Find and Tame High-CPU Processes

Sometimes the heat isn't a hardware problem. It's software working too hard.

On Windows: Ctrl + Shift + Esc opens Task Manager. Click CPU to sort by usage. If something is sitting at 50-80% CPU when it shouldn't be (a browser tab, a background updater, malware), that's generating significant heat.

Common culprits: Windows Search indexing (temporary, usually), antivirus scans, browser extensions gone rogue, and crypto mining malware.

If you see an unknown process using high CPU consistently, search its exact name to determine if it's legitimate.

On Mac: Activity Monitor under the CPU tab. Same approach.

Fix 4: Repaste the CPU (Intermediate)

Inside your laptop is a thin layer of thermal paste between the CPU and the heatsink that draws heat away from the processor. Over time, typically 3-5 years, this paste dries out and becomes less effective.

Replacing it requires opening the laptop, which varies significantly by model and voids warranties on some machines. If you're comfortable with small electronics disassembly and can find a service manual for your specific model, it's a legitimate DIY repair. Otherwise, this is a job for a repair shop.

The improvement can be dramatic. A laptop that was hitting 95°C can drop to 75°C after a repaste.

When to Get Professional Help

Some heat issues are hardware failures, not maintenance problems:

• Fan has stopped spinning entirely (you can usually hear this)
• Temperatures are extreme even right after cleaning
• Computer shuts off unexpectedly rather than just slowing down
• Temperatures climb rapidly within seconds of startup

These point to a failed fan, degraded heatsink contact, or in rare cases a failing component. Not something to DIY unless you're experienced.

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If your computer is throttling, shutting down, or running way hotter than it should, a SageTech tech can diagnose the issue at your home, clean it out properly, and tell you honestly whether it needs a repair or a replacement.