My children (5, 3.5 & 1) will play outside for around 10-15 mins then come back inside.
I only let them play in the garden (when it's sunny & hot and where there is no shade) before 11am and after 3 pm.
It seems to take me longer to apply sun lotion than they actually bother staying out. So, my question is would you ever let them play minus sun lotion and for how long??? With hats on but no long sleeves..