Disable template edit

Hi all.

I have create a template for newsletter for the site I manage, but it’s not me who has to create the newsletter.
The news will be created by users who know little about computer.
I have created a wordporess user with limited permissions, and write a guide to create a newsletter using my template.
The problem is that when a user opens a template to create a new email, can modify all the template (header, footer etc. etc. etc.) and can “ruin” the template structure.

Exist a way to “block” the different blocks (header and footer for example) of the model leaving free only those that the user can modify?

Regards,
Marco