Email notification for user role change

Is it possible to trigger an email notification to a user to let them know their role has been changed? I am setting up a site with an applicant / participant role structure, where the admin changes the role to participant once the applicant has been approved. It would be great if this triggered an automatic notification to the user.

Sorry, I might be spamming the forum a bit while working out the ins and outs of Kirby, but really enjoying it so far!

Hooks to the rescue, in this case:

No worries, we are here to help.

Perfect - thanks again!