My Husband Started Shaking Uncontrollably After Dinner (shrimp, Salad Pasta,

My husband started shaking uncontrollably after dinner (shrimp, salad pasta, rice) and also took some vitamins including Krill Mega 3, probiotic, and multi vitamin for Vision. Also has been under some emotional stress.
What could be the cause? He does feel warm but also is under a lot of blankets but says he is not cold.