HDdslr overheating solutions?

I run a semi-professional football media network and we recently pooled some resources and bought both a Nikon D5100 and a Canon T3i in a small effort to boost a little production value into our live broadcast. Most streams last 2 hours with a 10 minute break in between.

Both cams last about 5 minutes on a tethered viewing application before switching out of live view for overheating issues.

The question is if there are any pros out there tha have delt with overheating issues, and what have you tried? We're thinking about putting them in weather-covers with ice packs to create a super-cooled environment… Anyone have experience with this? We're trying to avoid awkward switching when a camera disconnects from the software…

In a pinch we can revert to a wireless iphone 4 stream but the low resolution (400x450~) is a pain especially with no AF lock on the webcam iphone app. We're trying to avoid this…

The res on the dslr doesn't matter as it is from a USB stream and runs at around 800x600 anyways…

Added (1). Alright guys, thanks for submitting your answers, but I figured it out myself. The Nikon D5100 ran my stream stress test for 60 minutes before the battery ran out, have not yet tested the T3i. Other than the battery limitation, I had no issue producing an ~800x600 web stream, at least not as far as overheating is concerned. Here was my setup for anyone else looking to try this:

Connect Nikon D5100 to the streaming computer (in my case an Asus Eee PC). Run Nikon Camera Control 2.9. Run Manycam as custom screen capture.screen capture the output from Camera Control, local record or stream to ustream, vokle, etc.

Once every 20 minutes, stop local recording (live stream and vokle/ustream recorder still works off of camera control), and restart recording right away.

D5100 1 Battery time as of 2/27/2012: 58 minutes.

note: I'm not sure what the output is for capture programs such as camera control or controlmynikon, but it works fine for live web streaming and you can use all of your lens

For what you are shooting, you need a real video camera.

dSLR's were never designed to be video cameras. CMOS sensors are just not up to the task

Look for a 3-CCD video camera to do what you want.

Wrong cameras. What you need is a camcorder. The dSLR was never meant to do video.

Yup, you really need a video camera for this sort of operation. You could just about get away with Canon's 7D, Nikon's D7000, or Sony SLT-A77. The common factor on these three cameras is the magnesium alloy body, which they use as a heat-sink for the sensor!

*I can tell you Sony's A77 does get mighty warm if left shooting video for an extended period.
** The maximum video duration may be artificially limited on the cameras listed to avoid the different import duties payable on still and motion cameras in some dominions.

For the type of shooting you are doing DSLR are not the way to go. The Nikon D7000 can go 20 min straight and that's about the longest of any DSLR that I know. In your case you need a video production camera. I have a good friend that streams events and they have a set up with special software and they shoot with very cheap video cameras. You might want to contact Absolute Digital in Seattle and ask for help. Http://www.absolutedigi.com/ They know how to get you going. You can speak with Rey or Stephanie.