Do you realize that you start to feel tired and lethargic after being out in the sun too long? Rest assured it is not a figment of your imagination. According to medical science, being out in the heat does bring on the feelings of drowsiness.
This is because your body is expending energy to cool you down.
In an interview with Live Science, Dr. Michele Casey, the regional medical director at Duke Health in North Carolina explained that your body is working hard to keep you cool, and this extra labor makes you feel tired.
“Your body, especially in the sun, has to work hard to maintain a consistent, normal, internal temperature,” Casey noted.
Dr. Casey further explained that this would involve your body regulating itself to keep its temperature constant. This could involve vasodilation, where your blood vessels are relaxed to enable more blood to flow near the skin’s surface. In turn, this allows warm blood to cool off, releasing heat as it flows near the skin.
A recent article on the BBC also highlighted why some people appear redder when they are feeling hot. This is due to the increased blood flow near the skin.
Also, the body expends sweat on the skin, which is cooled as the sweat evaporates. During this process, your body works harder which in turn causes your heart and metabolic rate to increase, leading to feelings of lethargy.
Lethargy could also be due to dehydration, which becomes worse when a person is hot and sweaty.
In addition, damage from the sun can also increase dehydration. The rays from the sun can lead to chemical changes in the form of pigmentation, wrinkles and burns, all of which can cause fatigue as the body begins healing itself.
After a sunburn, your body reroutes fluid from other parts of your body towards the burn to help the skin with the healing process. Because of this, your fluid levels in your body decrease which in turn reduces the perspiration output, causing more dehydration and fatigue.
If you are feeling warm and want to cool down with a cool drink, take note of what you reach for. Drinks such as alcohol are diuretic, which could increase dehydration. If in doubt, get plain water and have a salty snack such as pretzels or baked potato chips.
Most importantly, be mindful of the indications of heat exhaustion, which includes sweating heavily, a rapid pulse and feeling sleepy or faint. This could be serious and it is recommended to find a cooler room, hydrate yourself and see a doctor if you still feel unwell after an hour as you may be suffering from heat stroke, which requires emergency treatment.
When the body temperature exceeds 104 degrees Fahrenheit (57.7 degrees Celsius) or hotter, this could mean heat stroke, which is serious as it could lead to damage to the brain, heart, kidneys and muscle. keep yourself constantly hydrated and avoid going out during the day between 10 am and 2 pm in the afternoon, which is generally the hottest period of the day.
Symptoms to watch out for include high body temperature, nausea, vomiting, headache and changes in behavior, such as confusion, agitation or irritability.