It's 90 degrees in the shade and there's no breeze. You can't think straight and even a minimal amount of exertion wipes you out. What's going on? You may have an overheated brain.
Defense departments do studies like the one below in order to see how soldier's cognitive performance may deteriorate with extreme heat conditions and physical work. What happens? High heat and physical exertion impair cognitive efficiency - but not all processes equally. One of the sensitive areas is visual attention. So even just looking at something becomes hard.
The very pink brain in the graph represents higher visual evoked potential amplitudes in both prefrontal regions when test subjects exercised under environmentally hot conditions. So, it really may be too hot to pay attention (something to keep in mind if your students are doing summer school, or preparing to retake the WASL).
In this hot weather, be careful about dehydration in the kids, especially those are sports or even doing more walking than usual. Children in general have weaker thermoregulation and many (including those with more frail conditions, sensory processing disorders, etc.) may be poor judges of their own hydration and thirst. In studies of youth football in the summer, many kids were found to be dehydrated even before heading out to play.
- Drink cool sports drinks. Don't insist on water only if a child looks he's getting dehydrated. Drinks with water, sugar, and appropriate amounts of salts generally hydrate better than water alone because it allows the water to stay within the blood vessels. Heat exhaustion may cause hypoglycemia, so when a child craves juice, he may be dehydrated. Cold drinks also don't just taste better - they're better absorbed.
- To cool down, rest, take a cool shower or bath, and seek out air conditioning. Make clothing spare or lightweight.
- Don't ever leave kids in a hot car - even if the windows are down.
Finally, if you're not sure about the symptoms or first aid for heat cramps, heat exhaustion, or heat stroke, check out the links below.
Heat Stress and Cognitive Efficiency
Heat Cramps, Heat Exhaustion, and Heat Stroke in Kids
CDC Guidelines for Extreme Heat