I got my first two together a few weeks ago and now this one from the same group. The other two don't seem to have problems with each other and I often find them sleeping and laying very close. I have seen most people housing 2-4 adults together no problems, assuming there aren't multiple males.
When it comes to my geckos I like to view as If I were that little gecko would I wanna live here/alone, etc. This is why I spent close to 200 on supplies for them, I like them to be a little spoiled.
Additional information, I house them in a 20g tank with a dual light fixture with temp always around 95. They have 2 hides and a humid box, as well as fresh food and water bowls. There is no neglect here at all, my girlfriend and I love these little guys and take great care of them.
I have an old 10g but no heat fixture or hides. I was honestly just speaking out of paranoia, as soon as I read "cold gecko" i started to convince myself he was sick. There are no red flags I can see, he is aware, active, his eyes are fine, no signs really.
Hm - you could always post an underside picture and get the forum opinion; he/she might be too young to tell, but enough pairs of eyes might be able to at least make a good guess.He isn't much smaller, he may only be a few weeks behind on age, I just wish there was a foolproof way of sexing young geckos that haven't been incubated for a specific gender.
I think the way people go about saying things could be done in more of a constructive manner. The OP may not know all the correct ways of doings things. I'd say most of us didn't know everything when we got our first geckos, including me. Without knowing the temps in the tank then we cannot determine if the gecko is cold or not. It could just be from being brought into a new environment. The gecko actually looks healthy to me.
To the OP, all newly acquired geckos need to be quarantined for 30-90 days. It also can takes days for a new gecko to eat. Let him settle down and try feeding him tomorrow. Just keep an eye on him and you should be fine.
It will not be possible to supply the appropriate temperature without a heat light, the A/C is almost always on and I don't want the little guy to freeze!