I brewed an ordinary bitter 2 weeks ago,its still in the primary. The question is, how long do I need to worry about the temp. It's going to get over 90 deg here in Oregon. Is there still a danger of high fusel alcohol?

Whats the temp now? of your beer that is

I ferment everything at 50F.

The temp now is 73 deg. I just set it in a muck bucket of cold water and wrapped a t-shirt around it, I will put a fan on it when it cools down a bit. I lost the last batch because of heat. I need a better way, I would set up a fridge as a ferm. chamber but nos room.

High temps aren't good at any time but 2 weeks into the fermentation is much better than having a high temp during the initial period of high activity. Our temps in SoCal are also supposed to be in the 90's for the rest of the week and I'm in a similar situation with my dubbel that I've also had in primary for a little over 2 weeks. I have the cold water bath and T-shirt going too and I'm not worried about it. I think you will be fine.

Find a big coadboard box, freeze some 1L- 2L soda bottles, put your brew in the box and set the jugs of ice around the brew and pack some old cloths, towels anything for insulation and then wrap some blankets old coats what ever you can cover it with. I brew lagers and ale at whatever temp I want like this,year around. I have a lager that has been at 52' steady for two weeks. I change the jugs out every day thats the only draw back but I like checking on them anyway.You can't use the box more than a couple times but there not hard to find.
Cold boxes, they work and I live in south Arkansas.

Matthew, I think you've just pushed me to finally brew a lager. Considering Arkansas is much hotter than it is here in Vermont, I'm sure I could get it to work. What are you packing the insulation around? The cardboard box?

But, this is one reason I'm glad to be living in the frozen north, my basement is up to 62F and won't get much warmer, so I've got ~900sq ft of prime fermenting space.

Get all your friends to donate all there old clothes,coats,sheets whatever. pack one side of the box with a wad of cloth, enough to hold your themometer or if you have one them tape kind nevermind, but I stick a thermo. next to the carboy or bucket in between th cloth. You should get a box big enough that you can put two to four 2-L soda bottles around the carboy.
Then pack the rest around the outside to cover the sides of the box to insulate.You'll figure out how much you'll need. If you use airlocks you'll have to account for that sticking out, I don't use them, but when I use one I throw something light over that. Then cover the whole thing up with coats and blankets. I leave a spot where my thermo is to check but I know I'll have to change out the ice jugs daily. You'll figure out how to juggle it(pun) in no time. For a true lager you'll need to have an extra fridge to secondary in, but not realy. It's realy easy,I mean just put some thought into it. I been do lagers that way for ten or more years. The boxes will get wet and you have to put some cloth down under your ice jugs and change those out as well or it will get moldy but I never had any probems really.
Lagers, lot easier than you think

Lagering isn't a big problem, during the months leading up to and just after winter the garage is right around freezing a lot of the time, I only fear actually freezing the beer in there.

Sounds workable though, I figure I can get a few frozen bottles into the boxes my carboys go into anyway, or if not I can find something bigger, and with my temps a few old blankets over the top should do the trick. Probably give it a shot in a few months so my garage will be ready when fermentation is done.

Here I have to keep a close eye on things in the summer more but I have a room in my house
to brew in that makes it easier, central air&heat. Boxes and soda bottles, blankets easy to come by. Love my lagers
Matt