The Hidden Dangers of High Temperatures on Your Mac: What You Need to Know.
While people are at the greatest risk from high temperatures during the summer season, your Mac can also be at risk. An iPhone or iPad will warn you when it detects it's too hot before shutting down, but a Mac may simply suddenly power off. If it doesn't power down, you may be running it too close to its maximum capability and putting a lot of additional wear on components that might fail later.
The key to protecting your Mac is knowing the temperature of its internal components and keeping them within a safe range. Apple recommends using a Mac when the ambient temperature – the temperature around you – is between 50°F and 95°F (10° to 35°C) and 95 percent or lower humidity. However, internal components produce far more heat than the ambient temperature, with around 100°F or 40°C often the minimum at which they operate in normal indoor circumstances.
CPU, GPU, ports, and other elements shouldn't exceed about 192°F (89°C) for extended periods. At 212°F (100°C), you should figure out what energy hogs are making your computer work that hard or shut the system down for a while. You can use the Activity Monitor app in Applications > Utilities to look at Energy Impact in the Energy column for more specifics.
Modern Macs have an impressive number of power sensors to detect problems and manage fan speeds in models that contain them. These sensors can be monitored with the right knowledge or software. The Energy section of the Mac's Activity Monitor utility provides information on apps and the amount of heat they generate while processing.
For some Intel Macs, you can use Terminal or a free utility for basic temperature monitoring. In Terminal, enter the following command and press return:
sudo powermetrics --samplers smc |grep -i "CPU die temperature"
Enter your administrative password when prompted. This will provide a continuous temperature reading of the CPU's temperature. Press Control-C to stop the monitoring.
You can also install the free app Fanny, which offers a simple drop-down set of information in the menu bar or as a notifications widget. Details include the average CPU and GPU temperatures along with current fan speeds.
For any Intel Mac and M-series Mac, the utility TG Pro provides detailed monitoring and fan control. You can see the temperature recorded by every sensor in your Mac and for hard disks and SSDs that support the industry-standard SMART diagnostics. Information and controls are available both in a standard app window and a drop-down menu bar. You can also monitor the speed of internal fans and override Apple's settings.
