You can make your child more comfortable in their child restraint system and stop them from sweating excessively by following these recommendations, especially in the summer:
Block out as much light as possible. Use tinted windows, built-in blinds, etc.
Put a cover designed for the summer on the child car seat.
A chair in light colors accumulates less heat than one in dark colors.
Use sunshades to reduce the heat, especially when the car is parked.
Before placing the child in their seat, it is a good idea to air out and cool the car down first.
Maintain a pleasant temperature inside the vehicle and make sure the air vents do not blow directly onto the child.
Planning trips for early in the mornings, or in the evening means you will be traveling at cooler times of the day.
Take refreshments (not too cold) in the back of the car and ensure the child drinks regularly.
Put the child in light and breathable clothing.