Firecrackers and sparklers cause the most injuries. Severe burns, injuries to the hands, eyes and face, and even blindness or hearing loss can happen anytime something is burned. For example, legal sparklers burn at up to 1800° Fahrenheit, which is hot enough to melt gold. Severe burns happen every year. In addition, puncture-type injuries to an eye are common.
The safest way to enjoy fireworks is to attend a show by a licensed exhibitor.