So in general, regarding perishable foods like meat, most dairy, unshelled eggs and shell eggs (in the US) , cooked casseroles, and so on: if the food (or its perishable components) have been at room temperature for more than two hours, you should discard that food.
This directly effects how comfortable it will feel outside. Many times, relative humidity can be misleading. For example, a temperature of 30 and a dew point of 30 will give you a relative humidity of 100%, but a temperature of 80 and a dew point of 60 produces a relative humidity of 50%.
Humidity describes the amount of water vapor in the air, and the more water vapor that is present, the more humid it is. Most weather reports don't tell you the humidity, though, because the relative humidity is more relevant. This is the amount of water vapor in the air relative to what the air can hold. This is just like figuring out how much water is in a cup relative to the total amount of water that cup can hold.