X2!It's on the shelf in our area. Amprolium is not temperature sensitive and does not need to be stored in the refrigerator. I wouldn't leave it out in the heat but it doesn't need to be refrigerated
@Mbeans643, amprolium is very safe and will not harm the birds that are currently asymptomatic. However, you do NOT want to give any extra vitamins (such as Poultry nutri-drench) during the treatment time as amprolium (Corid) is a thiamine inhibitor. If you offer vitamins that have thiamine in them, they will weaken the treatment.
When the treatment is over, you may want to consider offering a probiotic to help heal the guts of any of the birds that may have been affected.