Hey Lucy,
Need to know what kind of tree it is to know if you can save it, but lets start emergency treatment STAT. (I don't know what that means, but they say it on doctor shows all the time...

)
First let's give it a good soaking. Warm water in a basin and put the whole pot in until it's nearly over the rim of the pot. Leave sit for an hour or two. Then drain and mist. Putting a clear plastic bag over the plant to help hold the humidity would be good; remove and mist daily until you see new growth and then leave it off. A humidity tray wouldn't hurt either...
A warmish room? Put on a sweater, girl! Your tree would like it a bit more coolish this time of year. You're not keeping it near the heater are you? Don't. Ever. Promise...
Misting is a must in heated conditions. Think of this as a puppy (that won't poop your rug) It needs to be watered and fed and loved regularly. This one won't chew your slippers or piddle on your bed if it gets neglected; it just dies. So
you must remain attentive, despite men and pubs and finals. Promise...
If this is a deciduous tree (one that loses it's leaves in the autumn) then all is not lost. If it's a tropical, we might still save it. If it's an evergreen needled type like a juniper, Bob's a goner already and all the kings horses and all the kings men aren't going to help (even if you have those sort of connections). And no more feeding until spring! Written by people that want to sell you fertilizer; that's what's wrong with those directions...
So to work, Lucy! Drop a line and let us know how Bob turns out; we'll be pulling for him...
Scott