I believe that would be true. It is absorbed through skin contact.
I can only relate my small "anecdotal evidence" to this. I was on the lowest dosage prescribed. It did help pain but my goal was not to eliminate pain, just to reduce pain enough to function without making our household miserable. I went through the range of alternative medicine before trying pharmaceutical stuff. My doctor tried several things that just left me sleeping or zombie-like with my eyes open. I didn't take anything like that longer than a few days. (To humor the doc and see if the effect would wear off)
The only adverse side effect from the fentanyl patch was if I were outdoors and the patch was in bright sunlight. And I'm explaining all this because it relates to your premise. When sunlight hit the patch I would become dizzy, nauseous and my heart rate would increase. I learned to wear sleeves when outdoors to protect myself from that. But in the event of an attack such as you describe the sunlight on skin exposed to fentanyl could be deadly. That is my opinion. The fact sheet on fentanyl does state to avoid direct sunlight.
What you describe makes sense for most applied applications as the sunlight would warm the skin and open the capillaries to allow for increased heat release from the body. The increased blood flow through the capillaries would then absorb more medication more quickly then at lower temperatures.
I hate to be the fly in the ointment, but how would anyone be able to disperse through the air? Drones? Private aircraft?