Clydesdales/Athenas (200+ lb / 91+ kg) - Big head helmet...with vents?

I currently have a Bell Triton that fits just fine. I need more vents - in the hot weather my head is cooking. Any suggestions on other larger helmets that might be cooler? My head is in the range where most are too snug but I have the Triton tightened up quite a ways.

I was eyeballing the Specialized Air Force 3 but that's a special order at local shops, which is a bit of a pain.

Well, I was going to recommend the Air Force 3 because it comes in XXL.

That's what I have, and it has lots of vents and it comes in a off-white color to deflect the heat. Much better than my old helment which was black (what was I thinking?).

How big is your head? Here is a list of large helmets (http://www.helmets.org/bighead.htm). The Specialized Air Force (in the largest size) looks like it is the exact same size as the Bell Triton (not the Kinghead Triton, the Triton).

How big is your head? Here is a list of large helmets (http://www.helmets.org/bighead.htm). The Specialized Air Force (in the largest size) looks like it is the exact same size as the Bell Triton (not the Kinghead Triton, the Triton).

24.5", or ~62 cm. Most helmets top out at 61 cm, so I am just past the convenient point on the head size bell curve. I know there's also the oblong/round head variable, I fall into the former category.

I've identified the Limar 737 as one candidate, it fits up to 63 cm. Some of the Louis Garneau helmets look like they might work too, they're said to fit a little bigger than their 62 cm size limit suggests.

I had a Giro Atlas Large size (still do I guess) but after a fall it is cracked and I need a new one. Does anyone know if you fit a Giro Atlas well, will the same sized higher spec Giro models fit well too?