We have a k-boom crane mounted behind the cab, and the truck has an upright exhaust stack. The operators seat is the same height as where the fumes come out and, when the wind is in the right direction, the fumes cause the operator to get sleepy and, yesterday, led to a sore throat, an ear ache and other symptoms of carbon monoxide poisoning. We've tried redirecting the stack, but wind direction and speed can still direct the fumes directly at the operator. We are going to try using a hose, like what is used when mechanics work on a truck indoors, over the exhaust, but the hose is not that long so I'm not sure how well it will work. How long can the hose be before it causes back pressure and impacts how the engine runs? Any other thoughts on how to divert the fumes?