Coffee is a no-no for a warmup beverage, it constricts the blood vessels. Plastic garbage bags wrapped around your legs as cheap rain gear should not be allowed to flap around in the breeze or they will melt over the engine, which makes some bikes look even better. Don't overlook all that engine heat that gets wasted, buy some aluminum foil, rolls, ham and swiss cheese and make a sandwich in the morning, and place it strategically on the engine, avoiding dripping gasoline, oil or exhaust fumes... at lunch time you the cheese will be melted... use the same method to warm up small rocks and put them in your pockets, etc...