preworkouts

Its super cold where i live up north. How do you warm your body up before you walk into the gym? Is there a hot drink that you mix up or do you take some preworkouts to get your heart rate going ?

looking to get some ideas for pre workouts cause the ones I use are always out of stock. I am reading about banned nutrition and how good their preworkouts are. I am willing to sub those in until my regular products get back in stock. Which one do you recommend for me?