At a minimum you might need the following ...

A small backpack (like a college backpack)
A pair of tough, comfortable sneakers
A couple of pairs of socks
A warm fleece jacket
Maybe ... a spare pair of jeans or sweats
A flashlight and batteries
A quart of water
Some energy snack bars

That combo of stuff should get you home ... even if you have to walk for many hours. Everything fits into the small backpack, and can be easily kept in some corner of your office.

I've been trying to tell the people in my company in Los Angeles to get this kind of gear together. Guess how many have actually done it? I bet less than 1% !!!

Pete