the shivering and cold feet and hands are all indicates fever even if his forehead seems normal , try to take a rectal or ear temperature if possible and it will be high . fever and barking cough are signs of upper respiratory tract infection , caused by viral infection , which is self limited disease and will ends by it own . control the fever , keep him hydrated is all you need to do , usually cough syrups won t take out the cough but it can ease it . If you notice any strider: high pitched sound when your son inspire , or you feel he is having difficulty breathing you need to take him to his doctor to assess him and measure his oxygen level , because some of these viruses can obstruct the airways and cause them to spasm . I hope this helps