The National Weather Service upgraded Wednesday's heat advisory to an Excessive Heat Warning for parts of the Tampa Bay area, with the max heat index forecast to be 115°F at times.
The warning is in place for parts of Polk, Hillsborough, Manatee, Sarasota, Hardee, Highlands and DeSoto counties from 11 a.m. to 7 p.m.
The heat index measures how hot it really feels when relative humidity is factored in with the actual temperature.
According to the National Weather Service, when the heat index is between 103-110°F, heat cramps or heat exhaustion are likely, and heat stroke is possible with prolonged exposure and/or physical activity.
"An Excessive Heat Warning is issued within 12 hours of the onset of extremely dangerous heat conditions," the website for the NWS said. "If you don't take precautions immediately when conditions are extreme, you may become seriously ill or even die."
A heat advisory was already in place on Wednesday, the third in a row this week, for the following counties from 11 a.m. to 7 p.m.
- Citrus
- DeSoto
- Hardee
- Hernando
- Highlands
- Hillsborough
- Manatee
- Pasco
- Pinellas
- Polk
- Sarasota
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The NWS said heat index values forecast and measured are actually for shady spots, and in direct sunlight, the heat index value can increase by up to 15°F.
The Florida Department of Health provides these general tips for staying safe in the heat:
- Dress for the heat. Wear lightweight, light-colored clothing. Light colors will reflect away some of the sun’s energy. It is also a good idea to wear a hat or to use an umbrella.
- Drink water. Carry water or juice with you and drink continuously even if you do not feel thirsty. Avoid alcohol and caffeine, which dehydrate the body.
- Slow down and avoid strenuous activity. If you must do strenuous activity, do it during the coolest part of the day – morning hours between 4 and 7 a.m.
- Stay indoors when possible. If air conditioning is not available, stay on the lowest floor out of the sunshine.
- Be a good neighbor. Check in on elderly residents in your neighborhood and those who do not have air conditioning.
- Don’t forget your pets. Make sure they have access to water, ventilation and shade.