Sponge baths with cold water or rubbing alcohol, or dunking children in ice water, are not recommended. With a fever, a child will lose more water, yet may be less interested in drinking. This can lead to dehydration. You can fight dehydration with frequent fluid feeds. Your child's fever and crankiness should go up and down with treatment, and may get slightly worse at night.
Some children have seizures with fevers, and they require immediate medical attention.
You can manage most fevers at home. Have a thermometer to record the height of the fever. Encourage fluid intake - children with fever can get dehydrated. Observe your child - parents can usually tell the difference between fussy and really sick. Cool your child - with sponge baths, and the medicines explained above.