2 Answers

Wet socks are good for this , Sounds weird but works wonders for a high fever in children. Take a pair of cotton socks that are long enough to cover the child's ankles. Thoroughly wet the socks in cold tap water. Wring out excess water. Put the socks on the child's feet and repeat process when the socks dry out. Some kids will hate this but usually after the socks are on they calm down and enjoy the relief it gives.Also Paracetomol will reduce the fever.

Most important you determine why they have a fever - consult Doctor strange all four children have a fever. Antipyretic therapy this being treatment of elevated temperature such as drugs containing aspirin in the form of trade name CALPOL for little ones or paracetamol for children over twelve years and adults   which are the most effective drugs for reducing a fever but must be given in the right dosage and frequency and according to instructions. Also tepid sponging helps.

These are brand names and can be obtained over the counter but it is important for you with four children with fever to consult a physician.