Sweltering Weekend Forecast Brings Excessive Heat Watch

CHICAGO (CBS) -- Chicago could see the hottest temperatures of the year this weekend, prompting an excessive heat watch starting Friday morning.

The hot and humid weather will start on Thursday, as high temperatures reach the upper 80s, and the heat index approaches the upper 90s in the afternoon.

Dangerous heat will move in Friday, with a high near 96, and a heat index as high as 115. Friday's temperature could approach the record high for June 29, when the mercury hit 97 in 1954. Any temperature above 95 would also make for the hottest day of the year so far.

Saturday is likely to repeat Friday's sweltering conditions, and there won't be much relief from the heat at night, with overnight lows likely dropping only to the upper 70s.

The National Weather Service has issued an excessive heat watch from Friday morning through Saturday evening.

During the scorching weekend, you should avoid strenuous activity outside, and spend as much time as possible in the shade or inside air-conditioned buildings. It's also best to wear light, loose-fitting clothes, and to drink as much cold water as possible.

You also should limit alcohol and caffeine, as alcohol can cause dehydration, and excess caffeine can add to the strain placed on your body by heat. If you do drink alcohol, officials recommend drinking two glasses of water for every alcoholic drink.

Officials also recommend checking on sick and elderly neighbors, as well as anyone without air conditioning.

Scattered thunderstorms early Sunday will bring some relief from the heat, as Sunday's high is not expected to reach above the upper 80s.

Next week also is expected to be hot and sunny, with daytime highs in the upper 80s or low 90s throughout the extended forecast after Sunday.

• National Weather Service