Application level storage or file read

[Glenn E Lanier II]

I'm trying to determine which approach is the best (realizing that is somewhat subjective). I have a header/footer for some web pages that can be modified by the client, although rarely. Initial thought (and current implementation) was to read file contents, at application start, into application storage area. Every session start will check file timestamp and reload data if needed (to prevent having to unload application by stopping IIS). However, realizing that the client has trememdously bloated HTML for footer (several 1000 lines), I'm wondering if simply reading the file each time would be more efficient. What is the general consensus and/or is there a better approach?