https://www.prbuzz.com/travel/328413-car-shade-for-windows-provides-the-right-amount-of-protection-f

Riding in the daytime on long car rides can cause babies to get miserable and agitated. More often than not, this misery is caused by the overexposure to sun and heat. This exposure to heat and harmful UV rays can cause reddening of the skin as well, which is synonymous to Prickly Heat.