BRISTOL, Tenn. -

With temperatures reaching the 90s several times already this summer, first responders are asking everyone to be aware of the dangers of leaving pets or children in your car.

Tuesday a new Good Samaritan law went into effect in Tennessee that excuses liability for a person who breaks into a car to rescue a child in danger.

Today we tried an experiment to see what happens when you leave a person in a hot car.

First of all, don't try this on your own. We had paramedics on stand-by the entire time and they monitored Lyndsey’s heart rate and blood pressure.

Inside the car we had a thermometer and a camera to record it all. Click here to see the raw video.

“It’s been about 10 minutes since I've been inside the car. The temperature now is 96 degrees inside here; that's four degrees hotter than it was when we first started," says Lyndsey.

Ten minutes later it only got worse. "So it's been about 20 minutes since I've been inside the car. The temperature is now 98 degrees. That's two degrees higher than the last 10 minutes when we checked it. I've decided to pull back my hair a little bit to maybe fan out to give me a little more air. I'm really starting to sweat a little more," adds Lyndsey.

Bristol, Tennessee paramedic Jamie Reavis says he started seeing changes in Lyndsey’s vitals. "About 20 minutes in it looked like Lyndsey’s blood pressure went down just a little bit, and that's possibly from all the profuse sweating. Her heart rate had went up a little bit to try to compensate," he said.

"It's been 30 minutes since I got inside the car. The temperature is now 100 degrees. It's gone up about 8 degrees since we first got inside the car. I'm told my blood pressure has changed just a little bit still sweating a lot," adds Lyndsey.

Reavis says in some cases it may not even take 30 minutes for the situation to worsen. "Eventually the sweating is going to stop and get dehydrated the heart rate can go up. You can get confused and a headache, and eventually go unconscious and die," he said.

"I just finished 40 minutes and the temperature inside the car is 102 degrees now. I checked and currently the temperature outside is 82 degrees," says Lyndsey.

Reavis says children heat up a lot faster than adults do.

That's why it's important to never leave a child unattended in a car. If you ever do come upon a child locked in a car, Reavis has some advice. "If they are alert and looking at you and they're conscious, take a minute and try to find the parent or caregiver. But if they seem to be in distress and unconscious, then it's probably going to be best to go ahead and get in the vehicle and get the child out," says Reavis.