Regg & Jermaine, if having headache or migraine, it could be a sign that the body is asking for more fluid or water.
Try cold water or lemon with water.
As for constipation, lots of fruits, vegetables, yogurts or prune juice. Personally, I don't like prune juice so I will eat the fresh prune from the supermarket or the dry ones, they help too.
Also I think the heat is a killer too, I was very nausea and tired the whole day yesterday, so I just sleep when exhausted and thank God, dh came back to fetch ds from kindy.
Sharon, you can try ginger sweet or even bitter chocolate but need to take lots of water.