Pregnancy can make it hard to adjust to a warm environment. Under normal circumstances, the human body cools off by sending extra blood flow to the skin and then sweating, which cools the skin as perspiration evaporates. During pregnancy, the baby acts as a tiny heat generator inside the mom, but the baby can't eliminate its heat by sweating. Instead, heat made by the baby transfers to the mom, who then has that additional heat burden to deal with, so it really is easy to become overheated during pregnancy. And when the mom's body temperature rises, the baby's is about a degree hotter than hers -- and excess heat is bad for the baby. Early in pregnancy, elevated body temperature (maternal fever) is associated with an increased chance of birth defects. So staying cool is important for the mother and baby's health as well as comfort.

So what's a mother to do?

• Drink lots of fluids to replace the water you lose from sweating. A chilled drink (nonalcoholic, of course) is a good way to help your body cool off.
• Try to stay in air-conditioned places, or at least near a fan. Fans work by helping your sweat to evaporate faster.
• A cool bath or shower will also help you cool off if you get too warm. If that isn't available, a cool cloth on your face and neck and/or running your hands in cold water may help.
• If you start to feel light-headed, lie down right where you are. Pregnant women have a tendency to drop their blood pressure because the blood pools in the legs and also gets diverted to the placenta. There just isn't enough left to get to the brain, and light-headedness and fainting can result. (The greatest danger in fainting is that you will fall and hit your head or abdomen.) Once lying down, ask for cool compresses for your face and neck and some cool water to drink. When you feel better, get out of the heat.
• If you are exercising outdoors, stop if you feel overheated. Swimming is a great exercise for pregnant women, and the safest way to work out on a warm day. The water cools you so you don't heat up as you move.
• Swollen feet can be a problem in warm weather. Keeping your feet elevated may help, but going swimming seems to be the best treatment for water retention. The pressure of the water on your body pushes the excess fluid back into your blood vessels, which then take it to the kidneys. You may urinate a lot after swimming, but your feet with thank you.