Air fryers are a genius invention, but due to their small size and need for food spacing, you may need to prepare several batches, which can cause the first few to get cold.
Fortunately, there's an easy solution. Because air fryers retain heat, you can simply pop your early batches back in at a lower temperature for a minute or two.
Since the food is already cooked, you just want to warm it back up. This method does require some delicate balancing and timing, but it'll all be worth it.