10. Dehydration
Dehydration is caused by fever, and can then cause a number of serious complications. For instance, dehydration may cause a dry throat, it can cause dry eyes, it can make the skin appear worse, it can interfere with digestion, and it can even lead to headaches. The latter is caused by the brain shrinking and then pulling away from the skull wall.
Thus it is extremely important that you keep giving your child lots of water if they have any illness, and especially if this coincides with an infection. They may have a loss of appetite and this combined with the aforementioned irritability can make it hard to get them to drink: but you must keep trying to ensure that they don’t become dangerously dehydrated.