This heat ='s scary stuff

So today Olivia and I were playing in her playroom, I went out back to get my cell phone and came back in and she wasn't in there. I assumed she'd went upstairs to play in her room so I grabbed a coke and sat down to watch Dr Phil. After about 3-5minutes I thought to myself its really TOO quiet in here so I called for her...nothing. So I got up and checked her playroom again, not there. Checked the downstairs bedrooms, not there. Back yard, not there. I ran upstairs, she was no where. I called for my mom to help me find her. I ran out front but couldn't see her anywhere, I started to panic. I walked down the block but couldn't see her...as I was walking back I saw her head pop up in the car window. Id left the doors unlocked and she went out into the car to get her princess shoes and had shut herself in there. Its 111degrees today. I have never felt so scared in my entire life. She was fine, but I was shaking. I just brought her in the house and locked the car and front door. I know I need to talk to her about this, I feel I lost the prime chance....I was just too scared to even talk.