I'm going to interpret this as "Four things to always have on your person in addition to typical daily ballast". Typical daily ballast is what most people have on them: watch, wallet, keys, and cell phone.

1) Flashlight - No working streetlight and the glare from passing cars kills your night vision. Not to mention most bathrooms don't have emergency lighting. You haven't lived until the lights go out while you're on the john.
2) SAK or MT - Being able to cut things is good, but a knife isn't a screwdriver or a bottle opener. Urban setting means more mechanization. Carry the correct tools for it.
3) Whistle or alarm - No argument. It's better than screaming and makes for cool keychain bling.
4) Pen and pad - Don't count on decent recall when you're stressed or tired. Remember all those history tests you blanked on? If it's important; write it down.

EDIT

As far as the no-knife workplaces: How do they feel about bladeless/scissors only multitools? Will they accept it on the technicality that there are no cutting edges or piercing points, or is it a blanket ban on personal tools?

Smartphone with USB cable, multitool, bandana, 50ft paracord.

I always had a phone with me. It was part of my job...

For sake of my sanity at work I always had my tablet and/or kindle, various chargers, cables.

swiss-tool, and pill fob on keychain.
Leatherman squirt Ps4
Lighter (Refillable Butane)
Quick release paracord bracelet w/ Whistle
Flashlight
Bandana
16GB usb key

Here's my two cents on bandanas. You can use it in a lot of ways, even when your not at your 100%, meaning no fuss or extra work required. Cutting up your shirt, pants can leave your skin exposed to sun, cuts, burns, etc.. If I have room, I keep on with me.

Somewhat related aside:

You know how you can watch 1 YouTube video, then follow a rabbit trail of related or semi-related YouTube links? Yesterday I found myself watching some of the raw World Trade Center footage from 9/11. Haven't done that in a long time.

It got to me. I thought of those people. Many were FUBAR-ed no matter what they did or carried. But how many would have made it out alive if they were more tuned in to the kind of thinking on this thread?

It saddened me.

The thread title calls for things that are "with you", not necessarily "on you". In that spirit some thoughts:

I agree on the knife, but a prybar or mechanical lever seems nearly as useful.

Heavy-duty gloves ought to be there somewhere.

I don't do the bandanna and do an N95 mask instead. I wear a vest and have room for a 3M folding N95 on my person but don't carry it since I'm concerned that constant flexure would harm the mask.

Goggles? If I don't want to breath it I probably don't want it in my eyes.

For some people keeping a set of safety footwear at work may be a good idea, i.e., something you'd wear walking across debris-strewn concrete, soft mud, and anything in-between.

This may seem excessive but I have a cheap AC voltage detector in the safety kit. If there's a bad storm that knocks down wires I can safely tell if they're live.

PS. I sure seem fixated on body protection. I should probably start with a list of firefighter's gear and work back to practicality from there.

No. No you can't. Assume that all downed wires are live until the power utility or fire department tells you otherwise. Your voltage detector will not be able to reliably tell if a wire is live before you get close enough to get shocked.

But why "Four Things" then? I'm hauling a 30 pound wheel bag (transformable to the backpack) to work everyday. Does that count a s 1 item? It contains hundreds of urban survival items though.

With 110v AC I seem to get about an inch away when the alarm starts, when sensitivity is turned up.

Better yet, Extech sells some where the probe is on a 3' insulated extendible stalk.

I probably shouldn't have mentioned it because it is way-out-there risky, certainly not anything I'd do except as last resort. But I have the tool and store it with the emergency gear, just in case...

PS. And, dead wires may not stay dead...

Under no circumstances should a homeowner attempt to verify whether a downed power line is energized or not.

The safe minimum distance is at least 10'. And 10' may not even be enough distance under some circumstances. So stay even farther away than 10' if you can. You NEVER want to hold and extend an object of any kind toward a potentially energized power line. It is possible that by doing this you could become a path to ground, and get electrocuted.

Call 911 in these situations. If you can't get through to 911, your best option is to put up a barricade, florescent tape, or cones to keep people a safe distance away from the danger. Then keep trying to get in touch with emergency services, power company, etc.

I cannot fathom a last resort for which this tool is appropriate for a downed power line. My suggestion is that you remove it from your kit.



Very true.



Ten feet should be considered the absolute minimum, and if the power wire is near standing water or anything made of metal give the same respect and clearance to those things.