I was visiting a freind with my 5-week-old yesterday, and my son started fussing. While he normally fusses quite a bit at that time of night, I can usually sooth him with a finger, rocking, and nurseing for a bit before he finally conks out.
However, none of that was working: He degraded into full-blown rage, red face and breath holding included. This upset thier 4.5 month old, and everyone got a head ache. I take him outside into the cool air to cut the noise down...
and he falls silent in less than two seconds. Apparently, a onsie at 75 degrees is way to warm for him. He has the same outfit on at home, plus a blanket when napping, and I keep it at 69-71, depending on who set the thermostat last. Even when outside in 40 degree weather, he seems happiest with a shirt and pants under a footed pair of pj's, with a couple blankets thrown on for good measure.
His hands and feet are normally cool, but any wamer than that, and I risk him sweating really badly.
It may have just been a coincidence that he stopped crying when you went outside. Going outside is what I do when I can't get a baby to stop crying, the change of environment tends to snap them out of it.
If you're concerned about his temp you can always take his temp with a thermometer but I think he should be able to regulate his temp pretty well by this age.
How much does your LO weigh? I know that once a baby reaches 8 lbs they are able to regulate their temp better and you can bundle them less.
My DS is 12 weeks old and about 14 lbs. If he gets too warm, he gets very angry--a lot like what your describing. Normally it's easy for me to tell that he's too warm because the back of his neck will be very hot and his back will be sweaty. We keep the house at 70 degrees and he is mainly in a onesie all day. I put a pair of socks on him because his feet always feel chilled without them even when the rest of him feels comfortable. When we go out to the 50 - 60 degree weather, I normally just throw a pair of pants on him and keep a jacket and blanket on hand if he feels cold. He seems pretty happy with this arrangement and I know he would definitely tell me if he wasn't comfortable! :)
Happily married to DH
Stay-at-home mama to DS1 (01/12) & DS2 (01/14)