Heat Exhaustion? Quickly Need Help!?

I have been out at the beach with my friend all morning and then we came home and sat in the garden. She said she felt sick and dizzy so went indoors and a few minutes later she collapsed. She have been sick three times since she woke up and said she feels really weak and shaky. I am getting her to drink water and lie down but I don't think its doing much. She doesn't seem confused but I think she is shocked by what happened. Do I need to take her to the hospital? Her temperature is about 38.1? She keeps telling me she is fine but I don't think she is :/