Your baby needs to be kept cool and safe from UV rays. It is recommended that the baby should not be exposed to direct sunlight for the first six months. Their skin is very sensitive at that age and it doesn't take a lot of sun exposure to burn them. To protect their delicate skin and keep them cool in hot weather, dress the baby in thin, loose, light coloured clothing, (preferably cotton or cotton blend) covering as much skin as possible. Keep baby shaded with hats and umbrellas. If you have a baby carrier with built in sun protection, nappies and a wide brimmed hat may be all the baby really needs.
Use sunscreen to protect any exposed skin every time you take the baby outside. Natural sunblocks like zinc oxide and titanium dioxide are the two of the best choices. They aren't absorbed into the baby's skin, keep the sun out and they don't contain ingredients that may harm tender skin. And since they remain on the top of the skin there is no need to apply them 30 minutes before you go outside. You may use synthetic sunblocks if zinc oxide or titanium dioxide are unavailable. It's better to protect your baby from the sun with than nothing at all. The chemicals in these synthetics may irritate tender skin so don't purchase anything with a SPF over 30; the higher the number, the more chemicals the product contains.
Liquids are very important during the hot weather and can play a major role in summer cooling. Ensure that the baby is well hydrated. To cool down on those extra hot days, try carrying a small spray bottle of chilled water in the pocket of your carrier.