The temperature outside directly affects the human body.
In the extreme heat of summer, or prolonged exposure to hot temperatures outdoors, your body works hard to regulate body temperature. It takes a significant amount of energy to maintain a normal and consistent body temperature, even more so on very hot days.
All of this energy use can cause us to feel tired and lethargic.
If you go out on a hot day, it may not take long before you start feeling tired and lethargic. But why does being outside in hot temperatures cause a feeling of drowsiness?
The reason for this sluggishness is simple: Your body is working hard to keep you cool, and this extra work makes you feel tired.
Your body, especially in sunlight, must work hard to maintain a consistent and normal internal temperature.
On a hot day, your body makes a number of adjustments to maintain its temperature. For example, by widening your blood vessels, a process known as vasodilation, which allows more blood to flow closer to the surface of your skin. This makes warm blood cool, releasing heat as it flows near the skin.
This increased flow of blood near the skin explains why some people look redder when they feel hot.
In addition to vasodilation, the body expels sweat to the skin. This sweat then cools your skin as it evaporates, but in order to do this extra work, your heart rate increases, as does your metabolic rate (the number of calories your body needs to function).
All that work raises your heart rate, your metabolic rate. and in the end make you feel tired or sleepy,.
Most people spend their lives a bit dehydrated. Being hot and sweaty only makes dehydration worse, and a symptom of dehydration is fatigue.
Getting damaged skin from the sun can also increase dehydration. When the sun shines on your skin, it can cause pigmentation changes and wrinkling. These chemical changes actually lead to fatigue. It’s because your body works to repair the damage.
Sunburns damage your body’s ability to regulate temperature. Moreover, when you are sunburned, your body diverts fluids from around the body towards the burn in an attempt to heal the skin. This shift means you have less fluid overall to sweat, which can lead to more dehydration and fatigue.
So that’s why your body feels tired when it’s hot.
Whether you’re at the pool, in the yard, or just relaxing in the shade, the heat will eventually leave you feeling exhausted. The best way to stop or even reverse this is by staying hydrated. Hydration replaces fluid loss caused by perspiration.
