That's a normal way for one's body to acclimate itself to new and more refined vibrations if you’ve let them in on one big wave.  There’s a lot of that going around these days as the world’s collective consciousness moves in its ascension vibration.

If you're sleepy, give yourself permission to put your head down and close your eyes to consciously allow the acclimation to occur.  Often, it only takes five to twenty minutes to fully acclimate yourself and assimilate a new vibration, especially if you do it with the intention of allowing it as well as with the knowledge of what’s going in within you.  You'll wake up more present, aware and energized than you were before you allowed yourself that small repose. 

Think of it like when you fly to higher altitudes in an airplane, you simply have to give your body the time to acclimate to the higher altitude.

If you don’t feel you can afford yourself that small nap right away - maybe you’re doing the Light Work somewhere out and about and you need to get back to your room or drive home - then move 

s l o w l y  and deliberately.  This, too, will give you a chance to incorporate the new vibrations you are experiencing.

If you don't follow your body's need for rest and assimilation, you'll find yourself resisting those new vibrations and, in turn, resisting a whole lot of other things going around you. 

Remember, our bodies don't know how to lie and they will tell us exactly what we need to do to take care of them and ourselves.  So, if you feel sleepy, rest!  If you can't right away, then rest as soon as you can.  Keep in mind, the longer you wait, the more toll you are putting on your body and the longer your body will need to assimilate the new vibration as well as transform the resistance you put into it.

Side story:  I'll never forget the time I went to Sedona Arizona twenty three years ago and learned this is a very direct way.  At the time, I didn't know anything about Sedona other than there were some really cool red rock formations.  Driving down from Phoenix, surrounded by all of this profusion of nature in all her green glory on either side of a winding road, I suddenly got very heavy headed.  I drank some coffee from my thermos thinking that a shot of caffein should do the trick. 

Ten minutes later, I was still fighting to keep my eyes open.  In fact, I had gotten to the point where my head almost literally dropped onto the steering wheel of the car.  The vibrations were simply too refined for my body to handle.   Had I not been subconsciously  trying to attune myself to them, it would have been a whole other ball game.  But, it was my Divine Soul who was guiding me to Sedona so it stands to reason that I would be trying to assimilate, albeit subconsciously, the vibration of the area.

The reality was, it was dangerous for me to be driving the car in that state and there was only one thing to do: stop and take a nap. 

I found a little area where I could safely stop and not have to worry about getting nailed from behind,  As soon as I turned the key to the car, my head dropped back and I was out like a light. 

Ten minutes later, my head popped up and my eyes opened liked a little jack-in-the-box will do when the lid is opened.  (Do they even make those anymore?).  I felt energized by the smile I felt swelling in my heart and drove the rest of the way into Sedona singing out loud, as refreshed as if I had just come off of a two week vacation. 

How I woke up to what Sedona is and what happened there is another story for another day.  This side story was just to illustrate the value of listening to your body and how it doesn't take much to co-operate with its needs.