If the underside of their neck is quivering, I believe that is them panting. Either way, they are stressed, and if you don't remedy it, you are almost sure to lose them.
Also, since the aquarium is very small (considering), and enclosed, there isn't much air circulation. I would surely say they are too hot. Where is that aquarium at? I never use anything more than a 40 watt bulb in an aquarium that is in the house, and that's only for very young (>1 week old) birds.
ETA: Sorry to have beaten around the bush, but my point is that if the temperature of the aquarium is too high, since it is enclosed and small, the buttons probably cannot get away from the heat. The whole temp of the aquarium would be too high. If you start getting pasty butts on your seramas, then you will know for sure. But you should really have a bigger brooder, or not have a regular heat-type bulb in that one. I would think a 25 or 40 watt bulb would be more than enough, and you can always cover part of the top to help keep the heat in.
Button eggs are out like 4 weeks
How are the chicks this morning?
Did you get a temperature reading in there? I would say at there ages you don't want it over 90
Also make sure they do not start picking on your chicken ckicks Buttons can be mean little buggers!