Purchased said prawns from Tesco on Saturday evening at around 7pm. The sealed packet was left in the bottom of the shopping bag in a cool kitchen until around 7am Sunday morning, when they went into the fridge.
Today I ate them all (cold) in a salad for dinner.
Tasted fine 
Do you think I need to be worried?
YABU- I’ll probably be fine.
YANBU- Prepare to be ill.