Borgs can now be lit on fire and take heat damage as a result (3 burn damage max per tick as opposed to carbons hitting up to 8, and they also do not suffer from raised body temperatures)
They do not gain fire stacks from plasma fires, but can gain stacks from other sources
Are affected by extinguishers, showers, and the like as normal

Lighters can now ignite someone who have fire_stacks
If you've got fire_stacks and you start smoking a cigarette or cigar, or you are already smoking and gain stacks (such as someone spilling welding fuel on you) you'll ignite