Oh yes, I forgot, you will be biking there.
But, chances are that you will be sweating a little by the time you get there. Also, you're body will generate a lot of heat, so you'll welcome the cooler conditions! But, as your body stabalizes, you'll start to adapt to the exterior temperature, so that's when you'll put on your double t-shirt. Obviously, you're not going to ride with both t-shirts on! Only when you start to feel cold.
Also, you might want to bring some water judging your distance. Better stay hydrated!
Trav.
