HOUSTON -

The mercury is inching closer and closer to the 100 mark, which can be dangerous to many, especially women who are pregnant.

Summer also happens to be the peak time for births in the U.S.

Doctors say the average hospital in the Texas Medical Center might have about 325 deliveries a month. But in the summer, that number can be nearly 500 births!

Stephanie Kyzer is happy to walk into the A/C for her check-up at Texas Children's Pavilion for Women.

Kyzer expecting her second baby in October, so she still has to endure a full Texas summer.

Kyzer told Local 2, "I feel like I'm ready to have this baby because it's so hot."

Doctors call this time of year the "summer surge" as hospitals increase staffing and open more patient and operating rooms to prepare for the increase in births.

OB/GYN Dr. Susan Raine with the TCH Pavilion for Women told Local 2, "Some people will tell you that well there's a summertime boom in deliveries because in the winter time it's chilly and everyone likes to cuddle up. But if you really look at the data, that really doesn't make sense because it's as true in Houston as it is in Boston."

Though doctors really can't explain the baby boom, they can focus on patient care.

The number one concern is dehydration, which can be dangerous to mom and baby.

Dr. Raine added, "So what I tell my patients is always have a big bottle of water with you and drink it even when you're not thirsty."

The heat and humidity may also increase pre-term contractions.

Dr. Raine said, "Now whether in turn that develops into preterm labor is uncertain, but they will definitely feel more cramping and pain as they become dehydrated."

Expectant moms still need daily exercise, but doctors say avoid direct sunlight, apply sunscreen and take it inside if it's too warm.

Kyzer said, "I go for walks in the morning and if I do, it's at 7 a.m. so it's not so hot or I go in the gym and do swimming or Pilates, but moderate, not too extreme."

Dr. Raine also wants patients to know that swimming is a great escape from the heat for pregnant women.

Despite some old wives' tales you may have heard, she says swimming is a safe and fun activity to keep expectant moms cool.