Fan running constantly since update

I did the 2015 update this morning and my fan has been running ever since (from the very first reboot). In the 2 years I’ve owned this laptop, I’ve probably only heard the fan 2 or 3 times. Is anyone else having this issue?

  • Which Avast…? (Free/Pro/IS/Premier)
  • OS…? (32/64 Bit…? - which SP…?)
  • Other security related software installed…?

Paid -Internet Security

win 7 64bit

none

Probably related to NG. After first install, it sets up its environment.