Tabs auto-reloading in Firefox?

[ChaosBasilisk]

Apologies if this is simple to do, but after going through all of the settings rather extensively a couple of times, I still cannot locate what setting is responsible for auto-reloading tabs? I use this app for work and sometimes have to parse through months worth of data. The frustrating part is when it refreshes automatically and I have to start from scratch every few minutes. Can anyone help me figure out how to disable this?

TIA!