As the Fourth of July approaches, officials are warning the public against using illegal fireworks and reminding residents to take precautions against dehydration and other hazards.

“Fireworks in no way, shape or form are allowed in the city of Glendale,” said Glendale Fire Battalion Chief Greg Godfrey. “Every year there are a number of people, especially children, who are injured by fireworks. They are basically an explosive. It can blow fingers off, or take your hand off.”

A blaze in the San Gabriel or Verdugo mountains could be disastrous, said Godfrey, adding that fire and police officials plan to deploy special patrol units to search for illegal fireworks.

Dehydration also triggers numerous emergency calls, Godfrey said.

“We have a tremendous number of people who go out on the Fourth of July and do outdoor stuff, which is great,” Godfrey said. “But if you look at the temperature this week, it is expected to rise.”

Low clouds and fog are expected to burn off Wednesday morning, clearing the way for blue skies and daytime temperatures in the mid-80s, according to the National Weather Service.

Community leaders in Glendale and La Crescenta are preparing for a festive and busy holiday. For the sixth consecutive year, the Crescenta Valley Fireworks Assn. will stage its namesake show at 9 p.m. Wednesday.

The event is expected to sell out, attracting 4,000 people to the field at La Crescenta Elementary School and thousands more to the surrounding streets, said association member Steve Pierce.

Pre-sale tickets are $7 and are available at the Crescenta Valley and Montrose chamber of commerce offices, as well as Jay’s Maintenance and Bob Smith Toyota. Children under the age of 7 are free.

Funding for the $45,000 fireworks show largely comes in the form of private donations.

“It is not a cheap event, but it is certainly worthwhile because it brings so much joy and energy to the community,” Pierce said.

The gates at La Crescenta Elementary will open at 4 p.m. Features will include carnival rides, live music and food trucks.

“This is a very family-oriented event,” Pierce said. “There is no alcohol, no smoking. We have private security, we have sheriff’s officers, we have the California Highway Patrol. We never have any problems.”

Public safety officials are urging motorists to exercise extra caution when taking to the roadways. A special Los Angeles County drunk driving task force will stage sobriety checkpoints and deploy extra patrol cars Tuesday night and Wednesday in Glendale and elsewhere.

Other common safety hazards on the Fourth of July include improperly handled barbecue coals and unsupervised pools, Godfrey said. Coals should be left in the barbecue for several days until completely extinguished, he said.

“We have had cases in past years where we have people take coals out of the barbecue, put them into a bag, put the bag in a trash can and put the trash can in the garage and the garage catches fire,” Godfrey said.

In addition, all bodies of water, no matter how small, should be supervised, he said.

“If you are going to have a large group, make sure someone is watching the small children because it is too easy to lose track of them,” Godfrey said. “We don’t want any tragedies this week."

Twitter: @megankoneil