Must have been a drastic temperature change for them and they blasted. It happens all the time so don't fret. Just put it under either a flourescent light or East window (they are a low light plant) and make sure to water it about twice a week depending on the medium and size of the plant. You know...the usual stuff.
Cut the spike back close to the stem. Let it rest for a week or two then start using a water soluable fertilizer. 20-20-20 is fine. Use as directed until the end of September every time you water.
When it starts to cool down at night, put the plant somewhere where it will cool at night. Don't let it go below 60 degrees F. Stop fertilizing and just water when dry. That should kick it back into gear and you should get another spike.
Welcome to OB.
You were lucky to have Phal flowers so long. Phals usually bloom once a year if there is a single spike. If you have a spike that branches out from the single spike you have a branching type. They bloom for months & months && months.
Like Frank said cut the stem back. Make sure you do not get and leave any water in the crown of the plant (crown rot). That's the top where the leaves grow from. You want to make sure the roots get thoroughly wet in the medium and then dry. Then water again. I don't know what your phal is planted in but probably spagnum moss. Don't keep it soggy or your roots will rot. You might try soaking it in a container (premix the fertilizer and add) for about 5 - 10 minutes, drain off the excess water and check it in about 5-7 days. Don't reuse that mix for the next week. Fertilize weekly or each time but remember to at least once a month flush out all the accumulated stuff the fertilizer leaves behind. You can skip the fert. that time.
At some time you will need to repot and that is another story. If the moss seems to be getting nasty looking and roots not look so green (wet) and white (dry) check back and you will for sure get advice....lots of it
Keeping your chid healthy will reward you next time. Hope this helps. Happy Growing!