Shrieking cry

Hey ladies, my 13 week old is usually a very happy, content baby but we’ve been up pretty much since 2.30am as he suddenly starts screaming and crying inconsolably, this afternoon he felt hot & a bit clammy (forgot to take his temp) and his belly is hard, he had some calpol at 5. He’s feeding as normal, maybe a little more for comfort but I’m just not sure what could be bothering him :( Any advice?