> Can any on the list explain the reason for the cough
> caused from being around millions of bees?

It may be just from yelling over the roar of the bees for an extended period of time. Every time I'm at a party, or a concert, or even some loud bar or something, I have a sore throat the next day from just trying to talk to the person next to me. If you are doing this often a thing to try would be a PTT "family band" radio with a headset. That way you could communicate with your helpers, even if they are by the truck or out of earshot somewhere. "Hey, while you are by the truck could you grab me the ...". It may make your efforts easier all around.
Steve