How can you tell if the skillet is hot enough without a thermometer?
If you don’t have an electric skillet or a kitchen thermometer, the easiest and safest method of determining whether your oil is ready to fry is to stick the end of a wooden spoon in it. If you see many bubbles form around the wood, the oil is ready for frying. If it is aggressively bubbling, reduce the heat and let it cool off a bit.