not likely he should be healled
Hi
Welcome to the MedHelp forum!
If it is a simple flu then no, there is no danger. However if it is streptococcal infection then this may affect the heart as well (though not all streptococcal infections affect the heart). It will be better if he consults a doctor as there is no way you can know for sure what the infection is. If symptoms do not abate in a day or two, he must consult a doctor. Meanwhile drinking hot fluids will help.
Hope this helps. Take care!