Microplasma Pneumonia, Pain In The Upper Body, Vomit, Normal Temperature. Advice?

10 year old son. Had micro plasma pneumonia 6 weeks ago. Two days ago complained of feeling cold and sick in the tummy. He tried to vomit a few times but nothing came up. He stayed home from school yesterday. Often cold then hot and sometimes out of breath. This morning woke up saying he hurt from his head down to the top of his stomach. He says his throat is also sore. Coughing infrequently. General feeling of unwell. I have taken his temperature and it seems quite normal.