Down the pub - the thread about nothing and everything

[VNA]

Never been in the situation myself but getting covered in the foam is OK, just keep the space in front of your face clear and you can break as the bubbles are full of air.

But it won't feed a fire?

And yeah it would be easy to panic in such a situation, and sometimes you'll never know until it happens - and then it could be too late.
I'm familiar with deluge systems.  They stress to us the active firing system must be disabled before you enter a protected area (there is still limited passive ambient temperature protection).  When it is on active, it will fire a whole zone of heads, and spray out absolute shit loads of water.  It suppresses the oxygen in the enviroment, to the extent it would be a threat to your well being - you might not get out.