Liquid fuel should always be contained in the correct container and

Flammable liquids must be stored in closed containers. Smaller quantities of flammable liquids can be stored in approved containers and portable tanks. Up to 1 pint of a Category 1 flammable liquid, or 1 gallon (gal.) of a Category 2–4 flammable liquid, can be stored in a glass or approved plastic container.

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle