I have been running about 6 miles a day and have had no problems, but when I try to run around 8 to 10 miles I start to get extremely cold. I usually have to stop so I can warm myself back up. If anyone has any answers to this please let me know. Thank You!

We are going to need more info than that.
Where are you?
What is the temp, wind, humidity, etc of your environment?
What are you wearing?

Also, it isn't normal to get cooler as you run so I'm wondering about medical stuff here. The only time I feel colder as I run is when I have pushed myself too far in the heat and then gone into some shade and stopped running. Then I feel cold, maybe a little dizzy with blurred vision but it passes in about two or three minutes.

Dehydration can cause wierd symptoms like feeling cold as well sometimes but then you are talking bad dehydration and you should have some other symptoms too.
Dizziness
Blurring Vision
Cramps
Hot and cold flashes
Clammy skin

All of these are possible.

You could also be on the edge of heat exhaustion. The same symptoms apply.

I don't really know but if you talk about the circumstances, maybe somebody with a medical background can help.