Pick the Right Clothes
If you’re going to be indoors, dress your infant in loose-fitting, lightweight garments, preferably made from a natural fiber like cotton, which absorbs perspiration better than synthetic fabrics. A good rule of thumb: “Dress the baby the way you’re dressed,” Dr. Epstein says. “If you’re wearing shorts and a T-shirt, that will be fine for her too.” For the outdoors, put her in light-colored long pants, a long-sleeved shirt, and a wide-brimmed hat to shield her face. Resist the temptation to leave her exposed on a gray day, since harmful rays can penetrate the clouds.
Provide Good Ventilation
Since a baby doesn’t perspire effectively, he can become overheated far more quickly than an adult. That’s why you should never leave an infant in a hot room or a parked car. Even a few minutes could cause his temperature to spike and, in extreme cases, may prove life-threatening.