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Home » Why Do I Feel Lethargic In The Heat During Summer?

Why Do I Feel Lethargic In The Heat During Summer?

The summer months mean more time outdoors, gardens in full bloom and lots of travel plans ­- but the season can also have a great effect on our bodies.

As heat waves begin to arrive and temperatures once again reach record highs, you might find yourself feeling completely exhausted.

This could be due to lack of sleep because of hot, muggy nights, dehydration and other reasons which may surprise you.

Dr Zulqarnain Shah, medical director at SSP Health and GP at SSP Health practice Colne Road Surgery spoke to the PA news agency about why you might feel lethargic due to the heat.

Heat exhaustion is a heat-related illness that can occur after you’ve been exposed to high temperatures.

If someone is showing signs of heat exhaustion, they need to be cooled down and given fluids.


— NHS (@NHSuk) June 11, 2023 5 reasons why you feel lethargic in the heat Bodies have to work harder in the heat “When the weather is hot, our bodies have to work harder to cool themselves down

“The body’s natural cooling mechanism involves increasing blood circulation near the skin’s surface and promoting sweat production. These physiological changes can lead to fatigue and a feeling of lethargy. It is essential to recognise that this fatigue is a normal response to heat and is typically temporary.”

Dehydration Low energy and tiredness are also common when you’re lacking hydration.

“Hot weather increases the rate of fluid loss through sweating, leading to dehydration. Dehydration can contribute to fatigue and make you feel even more lethargic,” adds Dr Shah.

“To avoid this, it’s important to stay adequately hydrated by drinking plenty of fluids, especially water. Aim to drink even when you’re not feeling thirsty, as thirst is not always an accurate indicator of dehydration.”

In the heat you should aim to drink when you are not even thirsty (Image: Canva)

Heat exhaustion “Prolonged exposure to heat can result in heat exhaustion, a condition characterised by symptoms such as heavy sweating, weakness, dizziness, nausea, headache, and muscle cramps. If you experience these warning signs, it’s crucial to move to a cooler environment, drink fluids, and rest. If symptoms persist or worsen, seek medical attention promptly,” says Dr Shah.

It’s important to pay attention to warning signs, as if heat stroke develops, this is a medical emergency.

Dr Shah stresses: “Heat stroke is a severe and potentially life-threatening condition that requires immediate medical intervention. It occurs when the body’s temperature regulation fails, and the core temperature rises dangerously high.

“Symptoms may include a high body temperature (above 39.4°C), altered mental state, confusion, rapid breathing, rapid heartbeat, and even loss of consciousness. If you suspect heat stroke, call emergency services immediately.”

— NHS England Digital (@NHSDigital) June 17, 2023 Sleep deprivation The extra tiredness could also be linked to poor sleep, as this can really suffer in the heat.

“Hot temperatures can disrupt sleep and lead to poor sleep quality. The body needs to cool down to initiate sleep, and excessive heat can make it difficult to reach the optimal sleep temperature,” explains Dr Shah.

“To improve sleep in hot weather, consider using fans or air conditioning, wearing lightweight and breathable sleepwear, keeping your bedroom well-ventilated, and using lighter bedding.”

Pre-existing conditions could get worse Many people living with chronic or long-term health conditions deal with fatigue – which may flare up during heat waves.

“Hot weather can exacerbate symptoms and increase fatigue in individuals with certain chronic health conditions. Conditions such as heart disease, kidney problems, and respiratory issues can be particularly sensitive to heat,” notes Dr Shah.

“It’s vital to be aware of your specific health condition and consult with your healthcare provider for personalised advice on managing your symptoms during hot weather. They may recommend staying in cooler environments, adjusting medications, or monitoring your fluid intake more closely.”