Old horse worrying me.?

I have an old 32 yr old 14.2 gelding connemarra. Weather is awful, wet but not that cold 15oC. He has shakes but only at the very top top of his legs and connecting area above legs, seems to be at back and front, and not all over his body? He has no front teeth as well they got a hole and so needs to be hard fed every evening with senior food because he cant eat the short gr. Could he be just cold or maybe colic or something else.