I've been swerving this as I've not been able to find anything concrete in the last year or two.
From what I can read in the rule book though, I believe that we're not eligible to make a temporary transfer.
So, my interpretation is that League 1 and League 2 clubs get an additional month after each transfer window to sign loans.
Re the emergency provision, there is nothing explaining any possible mechanisms to this so if there is any rule, it's entirely at the discretion of the board to apply to use it. What I believe though is that if a goalkeeper was to go out on loan, you could theoretically recall them outside of the normal window if the club your loaning to agrees.