Yes. Infants and toddlers lose heat more rapidly than older children. Dress them in one more layer than an adult would wear in the same conditions. However, avoid over-bundling as it can cause overheating. Also remember to never place a child in a car seat with a bulky coat; instead, cover them with a blanket over the harness. For more questions check out this article for dressing toddlers and this one for dressing babies.