Thoroughly inspect the areas where the foal will be during weaning. It doesn't matter whether it's a stall, a pasture or a lot. During weaning most foals are upset, active and more likely to injure themselves. Make sure there are no nails or loose boards that could injure a foal. Doors and gates must shut tightly so a foal cannot get a hoof caught between them and the wall, a post or under the door.
Most stalls have openings above the front and side wall partitions for ventilation.
Secure these so they have no sharp edges or holes where a foal could get its foot or muzzle caught. Gates shouldn't have sharp metal edges. Pastures need to have safe fencing and high gates. After weaning, foals are likely to seek their dam and may try to get through or over a fence or gate. In lots and pastures, weanlings need shelter from rain and hot sun.