Had a horrid crash - been told it was caused by temps...

Basically I had been carrying out a *lot* of resource hogging tasks:
Using WinMx, Giganews, extraction of a 700MB file, virus scan, playing a particularly draining game, etc.
Anyway, I hadn't checked my temps, but recently summer has kicked in with a vengeance.
Basically I started up a video in PowerDVD (An MPG) after 14 hours of all this, and as the application opened, everything locked up, and my motherboard made a tortured beep, followed by the HD spinning down.
Is that a classic overheating scenario?

Info:

Athlon Thunderbird 1.4
Asus A7V266
512MB Crucial PC2100
SoundBlaster Audigy
Creative GF4 4600
IBM Deskstar 40GB ATA 100
IBM Desktstar 13.3GB ATA 33
8x4x32 Cyberdrive CDRW
16x48 Samsung DVD-ROM
Windows XP Pro

Temps with side case on before summer: about 48C
Temps with side case off before summer: about 42-44C

Temps with side case on now: probably about 55C
Temp right now with side case off: 48C/28C

All the above are idle temps.

Another point is that I don't actually have any proper 80MM case fans sucking and blowing (gotta love that phrase) - instead I have 2 60MM YS-Tech fans.
But I *do* have a 60MM Delta screamer on the CPU itself on top of a Globalwin FOP38/32 heatsink.

My questions: Do I *desperately* need 80MM fans for the case to get the temps down universally?
Do my temps sound remotely healthy?

Finally - did my crash, as asked before, sound like a heat issue or something more sinister?

Cheers

With the difference in temps side panel on/off, you need some case cooling.

The best heatsink with th highest cfm fan around can only do so much: if you use hot case air to cool the cpu, you won't get good results.

How high are the ambient temps? We've all been struggling with overclocks, etc. this summer- just like last year, etc.
Summer just isn't good for overclocking!

Even before summer your temps were a bit high for my tastes: I try to keep my rigs in the low 40c area.

Also: I'm guessing your temps are all 100%load, right? Because if they are idle temps.....WOW! Way too hot.

Another thing that can help is ducting room air to the cpu- it gets the cooler air right to the spot that needs it the most.

Check out the Cooling section for ideas and tricks to get those temps down some, but here is one: use cardboard to make temporary side panels while you find the best locations for side fans.

Thanks for the response - I'll repost this to cooling and see what advice they can give me.

In response:

No, those were idle temperatures, which I said in the post. Musta missed it.

You're quite right - if I have hot/warm air in the case then the Delta can only do so much. Good point.

When you say side fans, do you mean drilling some holes to install extra fans? Once I've positioned them, I mean.