In a large office you should be able to locate several UPS's that can provide power for lamps, radios or be used to make a beacon of sorts.

As someone mentioned earlier, find out what skill sets your coworkers have that might help (medical, construction, exotic dancing, etc...)

-Blast

Go to my truck and bring in the emergency box.
Since it's a blizzard I have my snow gear in there too, so I would have multiple layers, and pairs of socks and a pair of boots.
Emergency box would have mountain house food to share.

Then I would do what blast said and find out what skills everyone may have that could come in handy.

Other ppl seem to have covered a lot of it after that... insulation, other food sources, water sources/melting, first aid kits, morale boosters / hot water, comm gear, heat source / fire if possible, snow gear, put a flag or some signage up to let ppl know you are there.

Make sure if the snow is continuing it is not blocking you in 100% and cutting off your oxygen.

This post reminds me once again I have a lot to do to prepare for winter still!

Excellent responses above. A few more ideas:

Survey the neighbourhood:
- Have a savvy team check out the neighbourhood for better bug-in locations (restaurants) and sources of material (construction sites).

Check loading dock and mechanical rooms:
- If possible, gain access to these, for everything from tools to cardboard (primo insulation) to metal trash cans.
- The big shredded paper bin down there can be stuffed into industrial-sized trash bags for rough sleeping bags or mattresses.

Cars:
- Have people bring EVERYTHING from their cars, or at least do a complete survey. Most people have no idea what can be accomplished with a tire iron, jack, cell phone charger, booster cables, etc., let alone the other junk in the trunk.

Utilities check:
- Telephone lines may still be up, but your office PBX system may go down when the power goes off (especially after backup batts are exhausted). An old-style phone plugged into a direct fax line may get your comms up.
- Some utilities such as natural gas may still be on, but the electrical controls are off. A location like a restaurant may still have heat in the kitchen.

Power:
- UPSs for computers provide clean backup power, but the internal batts are small. Isolate your UPSs and ration them for radios and comms chargers. If you have any LED desk lamps, these will provide area lighting for a long time. Don't let some clever bozo plug in the kettle or toaster though.
- UPS batteries are typically 12VDC. In theory, you can bring in a car battery to boost your available power. In some of these the inverter may not operate without an earth ground (plugged into the outlet).
- Ideally, some of the emergency lighting should be shut off to conserve the internal battery; but that probably won't happen until too late in the emergency.

Boiling water:
- Regular steaming mugs of tea or soup will keep people hydrated and warm their body cores. Not to mention the ongoing morale boost. But how to provide this?
- Most offices don't have a simple metal pot of a useful (group) size, nor any non-electrical means to heat water.
- Many insulated carafes have stainless steel exteriors and liners. With tools, you could separate these and make tea on a shredded-monthly-invoice fire outside the loading dock.
- Of course, as an ETSer, you'll probably have a largish pot, multi-fuel stove, and gas siphon in your car. Problem solved.

As others have said, the wild card (and biggest headache) will be dealing with medical conditions with limited meds, expertise and emergency response. Offices should encourage/require people to have 72 hours of critical meds with them at all times.

I work in a 275,000 sq. ft. rather complex building with total key card access (no metal keys accessible except through security and that's iffy because the lock-box with the key inside is behind a secure door - duh). Since power is out, I would break into the security office and get the metal key. I would then block open appropriate doors. I would either keep the key myself or designate a trusted coworker to be the keeper-of-the-key.

This, of course, in addition to the recommendations already described.

Note - I've been told some doors default to unlocked during a power failure and some don't. Maybe. I'm not counting on the tech who said that and I haven't seen the list of which doors would be unlocked.

Great topic.

Threadjack: my father lives in a 11 story co-op, that has a secured entry at ground level. This building has a "closet" that contains an electrical panel on each floor, for the units on that floor. City or state regulations--or maybe the fire marshal, I don't remember--require that these closets be locked, but that there be a key available at all times for access. The co-op's solution was to install locking knobs on each closet, chain the key to the door, and insert the key into the lock. "There: it's locked, and there's a key available immediately." Seems to be working OK for them.
</threadjack>

Uhm.....

My building would not be sustainable. Everyone who is more than 12 miles out (3 hour walk) partners up with someone closer. Secure what you can, and move out in a group. People break off as they have to, and they have a phone tree to call back and forward.

Are these things in the "normal" office emergency manual?

I would strongly advise against trying to light a fire in a modern office building, I doubt that you could get rid of the smoke without letting in more cold than the heat produced by the fire.

Most modern offices are quite well insulated, and inner rooms are unlikely to get below freezing even in severe weather.

Before anyone gets too cold or weak, a search of the premises should be undertaken, with the following aims

1) to locate anyone not aware of the presence of others.
2) to locate any functioning UPS units, and turn them off to conserve the batteries
3) to locate bottled water and food
4) to locate spare clothing and blankets.

In all but the simplest premises, make a list of supplies that can be retrieved later.
Remember that the emergency may turn out to be life threatening, or relatively minor.
If only trapped for a few hours, dont rush to break into vending machines (theft, criminal damage, dissmisal) But DO locate the machines, and tools to force them, ready for later use if justified.
Dont cause needless damage to the building or contents in the early stages of a blizzard.
You will look very foolish if the power is restored and/or evacuation arranged promptly.

If the building has a restaurant or canteen, then forcing entrance would probably be justified, and there should be food supplies and perhaps a gas stove.

Sanitaion should not be much of a problem, since offices have large numbers of toilets. Use each one several times, and then flush normaly when utilities are restored.
If all else fails, then use waste bins etc as toilets, placing the used ones in a cold, unused area.

If bottled water is not available, then the water from toilet flushing tanks can be consumed in an emergency.

If anyone has a gasoline/coleman fueled lantern or stove in the car, perhaps for camping, then this would be very useful indeed.
The limited fuel supply can be supplemented with that found in vehicles.

Like wise if anyone has a kerosene lamp or camping stove, then this should be used, if fuel is short, then use diesel fuel from vehicles instead.
NEVER USE GASOLINE/PETROL IN AN APPLIANCE DESIGNED FOR KERSOSINE/PARRAFIN.
If useing candles or lanterns and camp stoves, have additional fire extinguishers to hand.
These should be found throughout any office, gather up a few extras.

Many large buildings have a standby diesel generator, if there is one and it is running, attempt to locate it and see how much fuel remains, It may be possible to obtain more, perhaps from trucks in the parking lot.
If someone in the party has suitable electrical knowledge, it may be possible to reduce the load on the generator by turning off lighting in some areas, this MIGHT allow the use of a small electric heater, coffee pot, or microwave oven.

If the diesel generator failed to start, it would be worth inspecting it and attempting to start it, especialy if the party includes anyone familiar with such equipment.

UPS units are often found in offices, and can be used to power any low powered line powered appliances such as laptops, desk lamps, cellphone chargers.
The run time is very limited.
It may be possible to use one or more vehicle batteries instead of the internal batteries, but TAKE GREAT CARE miskates can kill ! No point in surviving the blizzard but dieing of electric shock or from a battery explosion.

AA cells are often used in wall clocks, and it should be possible to locate a number in a large office.
D cells are often used in air fresheners in office toilets, and again a fair number should be available.

Whilst in an emergency it is probably acceptable to go through other peoples belongings, be resonable and dont read private papers etc.
Leave a note explaining what has been taken and why.

Even my own response earlier shows me the mistake which is so easy to make.
First thing is to stop and assess the situation.
Nothing in the post says power or water services were lost and the biggest problems might be dealing with boredom and providing snacks while waiting for the weather to clear.