context: If you're a parent, it's a scene that's all too familiar. You put your hand on your sick child's forehead and it feels warm. Then the thermometer confirms your suspicion: He's got a fever. But if you follow some simple rules you'll make him more comfortable and keep him safe. Fever is a defense against infection. Your child's body is raising its temperature to kill the germs. In most cases it's harmless and goes away on its own in 3 days. Acetaminophen can lower your child's temperature. If he's older than 2, the dose will be listed on the label. If he's younger, ask your doctor how much to give him. Another option is ibuprofen if your child is at least 6 months old. There's a lot you can do to make him feel better. Put a cool compress on his head and keep his room at a moderate temperature -- not too hot and not too cold. Dress him in one layer of light clothing and offer a light blanket. You can also cool him off with a lukewarm sponge bath. And don't forget -- make sure he drinks a lot of fluids. Never give your child aspirin. It can cause a serious condition called Reye's syndrome. Avoid combination cold and flu remedies in young kids. They shouldn't be used in children under age 4. In older kids, it's unclear how well they work. If you decide to use a cold medicine, check with your pediatrician to be sure your child is old enough for the type of medicine you're considering. According to the FDA, no child under the age of 2 should be given any kind of cough or cold product that contains a decongestant or antihistamine, and caution should be used even in children who are older than 2. In addition, no child under 4 years of age should be given a product that combines cough and cold medicines. The possible side-effects can be serious and even life-threatening. If the doctor says it's OK to use a cough or cold medicine, then read the label before you buy and pick the one that most closely matches your child's symptoms. Don't switch back and forth between different medications without your pediatrician's OK. Don't use an icy cold bath or rub your child's skin with alcohol. Either can actually drive a fever up. And even if your child has the chills, don't bundle him up with thick blankets or clothes. Usually, you don't need to take your sick child to the doctor. But sometimes fever can be a serious warning sign. Call your pediatrician if he: Has a temperature of 104 F or higher Is under 3 months old and has a temperature of 100.4 F or higher Has a fever that lasts for more than 72 hours (or more than 24 hours if your child is under age 2) Has a fever along with other symptoms such as a stiff neck, extremely sore throat, ear pain, rash, or severe headache Has a seizure Seems very sick, upset, or unresponsive How often do you need to check? That depends on the situation. Ask your pediatrician. Usually, you don't need to take your child's temperature obsessively or wake him up if he's sleeping peacefully. But you should do it if his energy seems low. Which thermometer is best for kids? Digital ones are best. They can be used in his mouth, rectally, or under the arm. For young children, a rectal temperature is most accurate. If your kids are age 4 to 5 or older, you can probably get a good reading with a thermometer in the mouth. Under the arm is less reliable but it's easier to do. Remember to add a degree to an underarm reading to get a more accurate number.