Hair extensions are artificial or natural hair strands that are added to a person's existing hair to enhance length, volume, and sometimes color. They come in various types, including clip-ins, tape-ins, sew-ins, and fusion extensions.

The lifespan of hair extensions depends on factors such as the type of extensions, quality, and maintenance. Temporary options like clip-ins can last up to a year with proper care, while semi-permanent options like tape-ins or sew-ins may need maintenance every 6-8 weeks and can last several months.

In general, yes. However, it's essential to use heat protectant products and not exceed recommended temperatures. Human hair extensions can be styled with heat tools, but synthetic extensions may be more sensitive to heat.

Match the extensions to the mid-lengths and ends of your hair for a natural blend. If you have multicolor hair, consider extensions that match the lighter or darker portions. Some people also choose extensions that contrast for a highlighted effect.