Not enough detail.
One way is the verbal Rating of perceived exertion scale 6-20
Another is heart rate range compared to their Max heart rate 220-age
Explanation:
the answer to your question is you're probably hungry or just need to go to the bathroom
Is tax to be paid or an amount of money should be paid.
Google.
Carlos is correct because produce can go longer without cooler temperatures (think of farmer markets the produce is out all day ) but meat and poultry can get spoiled faster
