(WENY) -- With the extreme heat that's hitting the Twin Tiers this week, it's not only important to have a good grasp on how hot it's going to get, but also how it can impact your body, especially in a locked car.

Horseheads firefighter Art Sullivan and I wanted to show/tell people how hot and how dangerous it can be as minutes go by in a hot car.

When we got into the car around 1:45 p.m., it was about 90 degrees outside and roughly 100 degrees inside the car. We started by checking my pulse and blood pressure.

Art: "One-thirty over 82 right now." Linsey: "That's not too bad?" Art: "Not too bad to start with, no."

Both Sullivan and I began to sweat almost immediately after getting into the car. After about five minutes, the temperature went up significantly.

"Now we're at 109.5 and the windshield is at 120," said Sullivan.

He also asked, "Do you feel a little heaviness when breathing? I do." I replied with, "It's like you have to take a deeper breath, right?" Sullivan agreed.

After about 10 minutes of being in the car, the GoPro we used shut off, likely due to how hot it was in the car. To no surprise, my blood pressure also went up and I was in the beginning stages of heat exhaustion.

Heat exhaustion symptoms include excessive sweating, dizziness, fatigue, headache, and nausea. Heatstroke is a condition caused by your body overheating, usually as a result of prolonged exposure or physical exertion in high temperatures. Heatstroke can happen if your body temperature gets to 104 degrees Fahrenheit and requires emergency treatment.

Sullivan said up to 60% of your body is water. He said when you start sweating, you lose so much of your water. Sullivan said when you start seeing the signs of heat exhaustion, you need to take action quickly.

"You need to get into a cool place and get hydrated. Take sips of water slowly at first, and then take some kind of sports drink with electrolytes to replenish your body. In 30 minutes if you're still feeling this way, call 9-1-1 because the next step is heatstroke and that's where we get many deaths," said Sullivan.

According to the National Highway Traffic Safety Administration (NHTSA), about 40 children a year die from heatstroke because they were left or trapped in a car. According to the NHTSA, 53% of hot car deaths happen because someone forgot a child in the car.

Sullivan wants to remind people to double-check the backseat before getting out of the car.

"Just take a look [in the back]... Just cracking the window isn't enough. You cannot survive the heat that builds up in such a short time. Do not keep children or pets in your car. The windows in your car act like a magnifying glass and the heat keeps generating," said Sullivan.

Sullivan and I were in the car for about 16 minutes. We got out around 2:00 p.m. and the internal car temperatures reached upwards of nearly 140 degrees. This goes to show how dangerous it can be if you accidentally leave a child or a pet locked in the car for five, 10, or even 15 minutes.