Is this normal to feel this way in 90 degree heat?

Ok so today I was inside my house all fine and dandy, then decided to go outside(I live in Alabama so it was probably 90 something degrees) and I was only out there for like 2–3 minutes when all of a sudden I got extremely dizzy, I lost my hearing for a second, couldn’t think straight, couldn’t breathe so well, and my whole body just felt weak. It’s never happened to me before. Is this normal? Could it be because I’m pregnant? Has this ever happened to any of you?