A doctor can tell if your child has hand-foot-and-mouth disease by the symptoms you describe and by looking at the sores and blisters.
Roast the beets for 50 to 60 minutes. Cook the beets until tender, checking them by inserting a fork into the center of each beet. When the fork glides in easily, the beets are tender enough to remove from the oven.
1 Wrap the foil around the beets, sealing it as if it were a package. Place the foil package on top of a rimmed sheet pan to protect your oven in the even the foil package leaks.  Roast in the oven for 30 to 60 minutes, depending upon the size and age of the beets. Test with a knife for doneness.