I'm new here & a HUGE thank you for all the information.  I've been having episodic cluster headaches for many years now and have only diagnosed them recently.  Thanks to the web info. my dr. was able to confirm, but we haven't found anything that works yet.  Things like Imitrex seem to work once for me & I think I've found the solution, but then the next time - nothing :(
With this bout I tried the water tip.  I haven't been drinking all the water during the day, but I do chug a huge glass when I wake up with the headache, ASAP.  I've also been putting HOT wet face towels on the side of my face that gets affected.  Another site suggested almost a steam bath with tea, but I just started dipping a cloth into the liquid & then putting it on my face & eyelid as hot as I could stand it.  I found this very soothing.
The first night I tried it I had headaches at 12:00 am & 2:30 am.  The first one was the worst but only took about 40 min to get to a point where I could go back to bed.  The second one I was up quicker & it was only about 25 min. until back to bed.   The water did seem to stop the headache from getting worse than the point it was at when I drank the water.
Had the same 2 cycles last night at pretty much the same times & those didn't get as bad.  Maybe it was my mad dash to the water & the hot liquid. 
I was in the process of trying to get into the dr. to get a prescription for Oxygen, but this actually seems to be working.  If I don't have plans to leave the house I may try to drink the water every 1/2 hour tomorrow to see if that'll even break the cycle.  Only problem with that much water is trying to run errands & not spending most of the day in the bathroom!!
THANK YOU sooooooooooooooooo much for the help.  I still have what I call a residual headache throughout the day, which sucks but is bareable.  At least for now the water & hot, moist towel seem to be doing the trick & who can beat the cost of that!!!!
This has been the most successful I've been at managing the pain once I get a cluster headache, so I'm thrilled.  I'd love to be completely without them, but at least I haven't been going crazy this time.

Before I learned about O2 and other drugs that can give relief to me,  I used to boil a quick cup of tea, and try to drink it as fast as I could stand it, all the while breathing into the cup, and getting the steam to come up onto my nose, eye, and head.  But it was drinking it fast that would get that warmth into my body that seemed to help a little.  Maybe that can help you, along with the hot towels.

Now i use ice, because even though it doesnt feel as soothing , it seems to freeze the HA out of me faster.

good luck
christine