Is SPF50 enough on its own, or do I still need a hat and shade?

SPF50 is high protection, but it is not a reason to skip the other measures. The product itself recommends combining it with a hat, UV-protective clothing and shade during the peak sun hours (roughly 11:00–16:00). No sunscreen, regardless of SPF, blocks 100% of UV rays — SPF50 filters out about 98% of UVB when applied in the recommended amount, but the remaining 2% still reaches the skin, and the protection drops quickly if the cream is applied too thinly or not reapplied.

In practice this means: apply the cream properly, reapply every 2 hours and after swimming or towel-drying, and still use a hat and shade during the middle of the day. The combination of all three is what gives a child real protection, not the SPF number alone.