I don't think they can damage your gear. I would ask the exterminator about the fog they're using. Oils will cause tubes to crack.

Tell your friend to stop feeding his dogs crap. Fleas like sweet blood. Put those dogs on a good diet and your flea problems may very well disappear. Natural foods. Cheap ground meats and vegetables. No more dog chow or over the counter food. If he has to buy the over the counter stuff, Iams is generally good. Less added sugar. There are also treatments you can get in the mean time. They are expensive though unless you have pet medical insurance.

Thanks, hueseph.
Believe me, I've told him time and again about all sorts of things - proper pet diet, getting some actual medication, and just general cleanliness habits.
There's a reason my dog and home don't have this issue. There's a reason his living space looks like a cross between an episode of hoarders and an indiana jones movie.

Assuming the gear is safe from the critters themselves, I have two options:
1. Grab my gear and finish the mixing work I have to do at home (worried a little about bringing fleas back, but I do have a few deadlines,
2. Wait until the landlord returns, actually gets an exterminator in there, and make sure my tubes don't crack. At which point I get back to work.

I'm not liking either one very much at this point, but it's the situation I find myself in.
I'm leaning towards leaving the space and its associated negatives altogether, whatever the outcome.
I love the old church but it's becoming more and more apparent that the space just isn't conducive to getting work done on a regular basis...
Besides, given the dungeon down below, I can't rely on this or other issues arising in the near future.

As bad as the flea situation is, my concern would be for COCKROACHES!!!! If this guy is as dirty and unhygenic as you say he is, these nasty little critters WILL wreak havoc on electronics. They LOVE warm surroundings and leave their slimey excretions on circuit boards and the like. Get outta there and FAST!!!!

Thanks for your input fellas.

As you might have guessed, this was a situation that I knew might happen, but I wasn't prepared for the manner in which it blew up.
So thank you for your prompt responses.

In all fairness, I exaggerated the conditions slightly.
But only slightly, so I am well on my way to clearing out of the space.
It's probably a conclusion I would have come to on my own, but I'm glad that your thoughts coincided with my gut feeling.

Thanks again!

Put borax in your carpeting and work it down into the nap. The crystals are the exact size to stick in the hairs on the fleas cutting open their exoskeleton so they essentially bleed to death. Also works on ants and roaches, but in different ways. Someone makes a bottled version that allows you to blow it into the walls around outlets and switches (take the plates off.)

Cool I use that for ants, did not know it worked on fleas, thanks for that.

If your gear isn't racked up yet and if your racks aren't rolling, you now have a good reason to start that upgrade. You can throw some dog flea collars inside the racks for good measure as well as some Borax. And you can move faster when you have to bug out.....

Another anti-flea trick is to put a dish of water on the carpet and hang a light bulb about a foot above it. The fleas are attracted by the heat, jump towards the bulb and land in the water where they drown.