Is it normal to get fever 99-100 reading in armpit during cough and cold for toddler and fever will last for a day or two even three. Fever will come and go in these days

Yes, it is normal. Though, when we get a fever it is our body's way of telling us that there is some infection in the body. And when you say cough and cold, then in this case you know that fever has come because of cold and cough. It is also an infection in the body and the fever will go as soon as the problem is addressed. Sometimes, the cough and cold becomes fine as it takes two three days and body's immune system fight it out. And if it doesn't become fine on its own then you must visit a doctor.