A candy thermometer is a specialized kitchen tool used to measure the temperature of sugar solutions when making candies and confections. It typically features a glass or metal tube filled with liquid that expands and rises as the temperature increases, providing a clear reading on a scale marked with specific temperature points. These thermometers are essential for achieving the correct consistency and texture in various candy recipes, such as caramels, fudges, and hard candies. By ensuring the sugar reaches the desired temperature, a candy thermometer helps prevent overcooking or undercooking, resulting in successful candy-making.