Why not get a
Mavic 2 or Autel Dual that is equipped with a thermal sensor instead of messing with an
Air 2? The new
Mavic 3 will have a higher-resolution thermal sensor. Parrot USA is available as a thermal drone, and there is a cheaper thermal Anafi. There are lots of thermal sensors available for the gimbal on an Inspire or
Inspire 2. The Yuneec CGO-ET on a Typhoon H might be the least expensive of the thermal drones, is very low-resolution.
I don't think any of the thermal sensors for less than several thousand bucks would be useful for scanning a crowd for elevated temperatures and getting close enough with a drone big enough to fly it for more than a few minutes wouldn't be legal in most places.
This kind of 'thermal sensing' would be better done with a sensor mounted to something on the ground.
All this IMHO, of course.