We've waited long enough and now temperatures are finally back in the 80s. But to some, today's heat may have felt more intense than what the thermometer read and there's a few reasons for that.
Most of us have heard of the "heat index". It's a tool used by meteorologists to help convey the effect that humidity has on our bodies. Basically the more humid it is, the warmer it will feel at any given temperature. When the heat index is in the 90s, even well-conditioned athletes need to be careful if they're outside.
Today's heat index was in the mid 80s. Certainly warm, but not dangerous. But there's one very important variable that the heat index doesn't account for: the sun. An area in direct sunlight can have a heat index 10-15 degrees higher than what's officially measured in the shade.
Another thing to consider is our own physiology. Sweating of course is our bodies' way of keeping us cool, but after months of shivering through winter it can take anywhere from 2 to 6 weeks for our system to become its most efficient. If you notice that you start sweating more easily in the later months of summer, that means you're acclimating to the heat.
Even once we are accustomed to the new season, staying hydrated and out of the sun during the middle of the day will go a long way in staying safe this summer.