We don’t give you a chair until late morning for 2 reasons, both related to safety.
First, if we put chairs out before you arrive on Fair Day morning, they would be in the way while everybody is bringing in exhibits and setting them up. What’s more, some of you with tall exhibits would stand on the chairs to reach — and the chairs aren’t sturdy enough or stable enough for that.
Second, it gets crowded between the rows of exhibits, just with all the people. The crowding would be much worse if you students were sitting in chairs. We distribute chairs late in the morning, after most of the judging is done, when (we hope!) the crowding is less of a problem.
So, you’ll be standing most of the morning at EISEF. You should wear shoes that are made for standing.