Let's take Final Fantasy XIV save data/config files as an example (.DAT files).
Replace .DAT with your problematic extension (.sav, .ffxvmod, .fmd, etc.).
Instead of guessing Progid, do this:
Go to:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.DAT
For 90% of overheating problems, the registry is the wrong tool. You should first try: file regedit ff hot
Clear cache and remove extensions – A bloated cache or a malicious extension is a common cause of "hot" CPU.
Update graphics drivers – Outdated drivers force Firefox into software mode.
Check for malware – Some malware injects into Firefox, causing constant background activity. Let's take Final Fantasy XIV save data/config files
Only if these fail—or if you’re in a managed environment where about:config is locked—should you pursue registry edits.
Too many processes = more heat.
Effect: Limits how many separate Firefox processes run at once, lowering CPU overhead. For 90% of overheating problems, the registry is
Editing the registry is safe if you follow instructions exactly, but mistakes can break programs.
✅ Always back up the registry key before editing:
Below are legitimate (and safe) registry modifications that can reduce Firefox’s thermal footprint.
The Registry is not a primary tweaking tool for standard Firefox users. However, for IT administrators needing to enforce settings across multiple machines, editing the Registry (especially under the Policies key) is a powerful, "hot" method to control Firefox behavior.
If you meant something else by "ff hot" (e.g., "Firefox has a hotkey registry setting" or "regedit for hot corners"), please clarify and I’ll refine the report.
This guide focuses on common issues where double-clicking a save file, configuration file, or mod file doesn't open the correct FF game or tool.