it seems to prevent mosquito bites for a short amount of time, typically less than 20 minutes. mine definitely were so i used 3/4 cup instead of a full cup. the day was overcast but more importantly there was no rain and no wind! haven’t played for a few years now. you’d head to the store with the list in hand and buy exactly what was needed. if you’re in a pinch, you can use the microwave since cooking time will only take less than three minutes. 