First of all, I totally agree with @phillpower's findings thus far. I've damaged a laptop CPU due to lack of airflow, but didn't know it until some time later after reduced performance. Heat damage is permanent, but fortunately today's CPUs have thermal throttling built-in, which is intended to prevent damage.
If it's only happening in Chrome, have you tried running Chrome with different plugins disabled? This page has more information. Also try Incognito Mode, which disables extensions for the browsing session.
Does it happen in Internet Explorer? Firefox? If so, I think it points more at the wireless hardware and software on this particular machine. If not, then you might try resetting Chrome.
I don't want to keep dragging the thread out here (sorry phillpower2). @pjgoodman2, are you getting page redirects, or pop-up advertising, or other symptoms of malware? If so, we can re-open your malware thread, but it honestly doesn't sound like that is the case.
Good luck!
DanoNH,
It happens in Chrome, Firefox and IE. I have tried Chrome in Incognito mode and it is the same. And no, no page redirects or pop ups. Nothing to make me suspect another infection. I guess it's time to take it to a shop in case it is the CPU.
Thanks for all the help, both of you.