Best way to check for an actual temperature is by using a thermometer so you know the exact temperature your fever is.
But you can check for a fever without a thermometer by feeling you your child's Forehead and check to see if the forehead feels hotter than normal.
If the forehead is hot or warmer than normal then you or your child likely has a fever.
You might also feel your eyes stinging from the salt entering your eyes when you're sweating from a fever.