Buckle up for a big one: The longest heat wave of the summer begins on Sunday

The dog days of August still have some bite, with a five-day heat wave bearing down on the Northern Seacoast beginning on Sunday that will reach its zenith on Monday with a heat index climbing to 104.
The two most dangerous days will be on Monday and Tuesday when blazing sunshine will carry "a significant risk of dehydration and heatstroke if outside for extended periods of time." according to Accuweather forecasts.
The high heat indexes from Sunday to Thursday will be 100, 104, 103, 98 and 97, respectively.
Those without air conditioning will see some sleepless, sticky nights as well, with nightime lows ranging from the mid-60s to the low 70s.
High Ultra Violet indexes, which can cause damage to eyes and skin, will be at their worst Sunday through Wednesday.
The heat wave will officially break on Thursday with some passing thunderstorms, but the rest of the week will remain warm with highs close to 90.
A heat wave is defined as three straight days of more than 90 degrees.

Tips to beat the heat

City Hall is open Monday through Friday from 8 a.m. to 5 p.m. The Public Library is open Monday through Wednesday from 9 a.m. to 8 p.m., and Thursdays and Fridays from 9 a.m. to 5 p.m.
Residents are also reminded of the standard safeguards to keep you and your loved ones safe, including the following.
Never leave children or pets alone in closed vehicles.
Drink plenty of water, even if you do not feel thirsty. Avoid drinks with caffeine. People who have epilepsy or heart, kidney, or liver disease, are on fluid-restricted diets, or have a problem with fluid retention, should consult a doctor before increasing liquid intake.
Check on family, friends, and neighbors who do not have air conditioning and who spend much of their time alone.
Check on your animals frequently to ensure that they are not suffering from the heat.
Go to a designated public shelter if your home loses power during periods of extreme heat. Stay on the lowest floor out of the sun if air conditioning is not available.
Check the weather and listen to a NOAA Weather Radio for critical updates from the National Weather Service.
If you must go outside:
Avoid strenuous work during the warmest part of the day. Use a buddy system when working in extreme heat, and take frequent breaks.
Dress in loose-fitting, lightweight, and light-colored clothes that cover as much skin as possible. Avoid dark colors because they absorb the sun's rays.
Protect your face and head by wearing sunblock and a wide-brimmed hat.
Postpone outdoor games and activities.
Stay indoors as much as possible and limit exposure to the sun.
Residents should take action before a heat emergency and can learn more at www.readynh.gov/disasters/extreme-heat.