Before you head to the salon for your appointment, familiarise yourself with the two broad categories of curling techniques – hot perm and cold wave perm. Most, if not all, of the latest hairstyles fall under these categories. They are different in several ways.

There are essentially two key differences between a hot perm and a cold perm—unlike the hot perm, a cold perm (also called a cold wave perm) doesn’t use heat during its process and involves coating the hair in an alkaline chemical solution and then coiling it around curling rods to give it texture.

For fine hair, a cold perm is often best, while on coarse hair, a hot perm can create better results; you can discuss this with your hairstylist beforehand. Hot perms can take longer than cold perms and are often more expensive.

The end result is that a cold perm results in tight, defined curls while a hot perm results in looser, softer curls. Almost all perms use the cold process, but a few notable hot perm types include digital and straight perms.

Cold perms offer a tighter, more defined curl pattern compared to hot perms. The absence of heat makes it less damaging to the hair, but the results may not last as long as hot perms. Cold perming is generally more affordable, with costs typically ranging from $50 to $100.