Heat dome threatens half the U.S. ahead of Independence Day

A dangerous heat dome is expected to bring prolonged extreme temperatures to nearly half the country as millions of Americans prepare to celebrate Independence Day outdoors.

(CNN)- A dangerous heat dome is expected to bring prolonged extreme temperatures to nearly half the country as millions of Americans prepare to celebrate Independence Day outdoors.

Cities from New York to Nashville are taking steps to help residents stay safe. In New York City, officials are expanding access to cooling centers by adding real-time directions to more than 2,200 LinkNYC kiosks and deploying 15 mobile cooling outreach vans for the first time.

Forecasters say many areas will experience multiple days of temperatures in the mid-90s to low 100s, with high humidity making conditions feel even hotter.

The East Coast is expected to see some of the most intense heat, with cities like New York potentially experiencing their hottest temperatures in more than a decade.

The heat is also expected to persist overnight, providing little relief for people without air conditioning or adequate hydration.

Officials are urging residents to check on older adults, children and neighbors who may be especially vulnerable to heat-related illnesses.

In Chicago, one restaurant owner is helping residents beat the heat by donating dozens of air conditioners to people in need as communities across the country prepare for a potentially dangerous holiday weekend.