It really could be a lot of things, you would have to be more specific. How often are they gasping, and what kind of sounds do they make, if any? Does it happen in a particular area of the cage or at a certain time of the day? Or is it completely random? They both could be thermoregulating, choking on something (doubtful), or have a mild respiratory infection. It could be numerous things, or nothing at all. Be a little more specific on here and I/we can see what we can gather in terms of information. But in the end, if you are worried about anything healthwise your best bet is to get one of them checked by a reptile minded veterinarian.

David