I flew from Toronto to Costa Rica on Feb. 24th in perfect health. 3 days later my partner and I both were coughing like crazy and bringing up phlegm. The back of my throat became so severely painful that it was horrible to swallow. My phlegm was green in colour and then eventually had blood in it. I have now arrived home and gone to my local hospital, where I was told by a physician that I had a severe "throat cold". I have never heard of this. Anyway, he said I did not need antibiotics. but would last several days.Is it possible we became ill from the air on the plane during our flight to C.R. ? We were in excellent health when we left Canada.