You'll be fine. My yeast for my last batch I picked up before I went to the park. Yeast sat in the car, in the sun, for a couple of hours before I went and got lunch, and it sat in the car for about another hour, and then took it home and put it in the fridge. Used it about a week later and to be completely honest, it was my fastest and most active ferment yet. I would bet money that you will be fine.
Of course, making a starter sure wouldnt hurt anything.