PHILADELPHIA (WPVI) --Blazing hot sun and high humidity, even if you catch a breeze, it's not cool air.
"I'm not a fan of hot weather. This is just a little bit too hot for me," said Igor Samonov of Maple Shade, New Jersey.
Excessive heat can be dangerous and even deadly.
"As a matter of fact, this is the disaster that kills most Americans, and it's particularly more dangerous if it's prolonged, so we're now entering a period of several days of very high heat so it's really quite dangerous," said Philadelphia Health Commissioner Dr. Thomas Farley.
Dr. Farley says they're hoping to prevent any more heat-related deaths. There have been four in the city this summer during previous heat waves.
They've activated the heat line through the Philadelphia Corporation for Aging.
"Anybody, any age can give us a call, and we can see what we can do to help out, either give them a resource, give them some tips to keep cool or put them in touch with the medical staff that's here," said Chris Gallagher, Philadelphia Corporation for Aging director.
The very young and very old are most at risk for problems, but everyone should drink more water, avoid exercise mid-day and limit time outside.
Dr. Farley also stresses checking in on neighbors, especially the more vulnerable.
"Many of the people who end up getting severely ill or even dying are very much isolated. They don't really have family that's going to be checking in on them," said Dr. Farley.