Get notifications for high CPU usage

My new laptop has an M1 chip and no fan, and this is great, but it also makes it hard for me to find out when the CPU has been running high (and consuming more battery than usual).

How can I make it show notifications whenever the CPU has been running high for a while?

I use iStat Menus. This is the best paid app for showing, via the menubar, how your Mac is performing. In addition it also can send notifications for a number of performance related events - and that includes high CPU.

Here is the preference screen for setting alerts:

You can download iStat Menus for free and use it for 14 days before deciding whether to pay.