I recently worked with both 7 and 5D cameras and the 7D was overheating very often while the 5D NEVER happened it. Of course I used a lot the 7D because of the more magnified tele I was using, but still, when using the 5D for wide lenses it never overheated. Is that common or just happened to me?

I think from the frequent reading I've done about this issue over the last 6-9 months it is generally agreed that the 7D is more prone to overheating than the 5DMkII and many consider this to be a result of it's better construction (read tighter fitting body panels etc.) and other design aspect (2 digital processors rather than 1 etc.).

Having said that, I've never (ever!) seen the overheating icon on my 7D since I got it last November (I don't own a 5DMkII so can't comment on that) - but now the weather in England is heading for the "BBQ" or "Sizzling" summer that we've been promised....at last.... we'll see!

I recently worked with both 7 and 5D cameras and the 7D was overheating very often while the 5D NEVER happened it. Of course I used a lot the 7D because of the more magnified tele I was using, but still, when using the 5D for wide lenses it never overheated. Is that common or just happened to me?

Does that 7D has the latest firmware? it was supposed to extend the temperature higher before the warning icon start to display.

Khoi makes a very good suggestion - that I should have mentioned - although in my case, my 7D is still running the same Firmware it arrived with last year (1.0.9). I've never had any issues with it (overheating or otherwise) so I'm loathed to change anything!

Yes, my 7D has the update for 1.2!
Now is almost "winter" (18°...) here in center-west Brazil but other periods it get up to 42°C!! So I'm better buy the 5D to guarantee longer time... or even to swap cameras.

I found a solution for the summer here, but I don't know if it will spoil my camera: I keep my batteries and cards in a cool bag, then when it stars to over heat I changer for the cooler ones... It helps and extend my filming time...

I just got the temp warning on my 7D for the first time over the weekend shooting a wedding photo shoot. But, I was shooting in 89 degree weather for about 75 minutes (on and off, mostly on) before getting it. It happened once, I turned the camera off for about 10 seconds, turned it back on and I was good to go for another 10-15 minutes. Happened again, so I took a short break and took out the battery for about 10 minutes. Put it back together and I was fine the rest of the day.