To keep your baby cool when they are sleeping:
Make sure that air can move around your baby by removing any padding around the cot.
Use cotton sheets to absorb sweat and prevent prickly heat rash.
Put your baby to bed in their nappy only.
Remember to make up their cot according to the safe sleeping guidelines. Always place your baby on their back to sleep and make sure their head is uncovered.
Think about moving your baby's cot to a cooler, well ventilated room in the house. Use curtains or blinds to block out direct sunlight where practical.
Keep the windows open to maintain airflow. If you are in a hot climate, use an air conditioner or a fan. Make sure that the cool air doesn't blow directly on them.
Expect your baby's sleep patterns to change when the weather is hot. They may be sleepier in the hotter parts of the day and have bursts of energy when it cools down.
Never leave your baby to sleep in a pram in hot weather.