Further to Foxmoth's post........
In 'theory,' it is considered unwise to open exits on the same side as a fire. In practice there are many variables to be considered. The British Airtours B737 disaster at MAN showed that you should never 'discount' exits on the same side as a fire. The
only 'useable' exit on that aircraft controlled by crew was the front port exit. Both rear exits and the port overwing exit were affected by fire and the FWD starboard exit jammed. The FWD port exit was initially ignored as SOP's at the time stated not to open exits on the same side as a fire. It was eventually opened out of necessity!
It is the cabin crew member at the door, on the day, that decides whether an exit is useable or not, provided it is not directly affected by fire.
For this reason, my company's SOP's do
not recommend that Op crew nominate which exits to use in the "Evacuate, Evacuate" PA. They can not see the extent of any external fire.