Scorching heat and UV rays: Why you need to take care

‘Heat wave’ has become a common term in Kerala of late. However, this time, there is an added warning of high UV index. TNIE looks at what this means, and the precautions people need to take

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Updated on:

11 Mar 2025, 12:30 am

5 min read

Heat dominates conversations among Malayalis these days. And the term ‘heat wave’ has become part of common parlance, as the soaring temperature leaves people weary.

This summer, however, fear is not only about heat stroke. Another concern has emerged — UV or ultraviolet radiation.

In 2020, the Kerala State Disaster Management Authority (KSDMA) had launched a project to install UV readers across the state. Today, every district is equipped with these devices and the readings are accessible on public platforms.

“For UV levels, there is already a system in place to determine when they become hazardous. If the level crosses a threshold, an automatic alert is issued — red, orange, or yellow. For this, we do not require historical data analysis,” explains a senior KSDMA official.

The World Health Organization’s Ultraviolet Index is divided into five categories:

0–2: Low (green)

3–5: Moderate (yellow)

6–7: High (orange)

8–10: Very High (red)

11+: Extreme (violet)

On Monday, Kottarakkara (Kollam) and Munnar (Idukki) recorded worrying UV levels — both at 8. Ernakulam and Thiruvananthapuram recorded 5.

Notably, along with temperature readings, KSDMA has been listing UVI as well. As per WHO guidelines, sun protection is recommended when the UVI is 3 and above.

“The high readings are primarily due to a lack of cloud cover,” explains Vijayakumar P, assistant professor at the department of environmental science, University of Kerala.

“Typically, afternoon clouds filter UV rays, but in recent years, summer showers have decreased, leaving the sky clear during peak sunlight hours.”

With real-time UV readings, the state now has a clearer understanding of the intense summers it has been experiencing. “After Vishu, when the sun is directly overhead, temperatures will start to drop. If heat levels rise further in the coming days, we can expect summer showers,” Vijayakumar adds.

Dr M M Faisal, former president of the Indian Association of Dermatologists (Kerala Chapter), says there is no alarming crisis or need to panic over UV radiation at present. “However, though people are not directly exposed to the most harmful UV rays, it is better to be well-informed about the dangers,” he adds.

Ultraviolet radiation, he explains, is classified into three types based on wavelength:

UVC: The most dangerous, but blocked by the ozone layer.

UVB: Affects the skin’s surface, causing sunburn, skin darkening, thickening, and increasing the risk of skin cancers like melanoma. It can also damage the eyes.

UVA: More prevalent than UVB, causing hyperpigmentation, dark spots, and skin diseases like photodermatitis.

“Indians are less predisposed to skin cancer than Europeans, so the risk is lower. However, protecting skin from UV radiation is crucial during peak summer,” Dr Faisal stresses.

Dermatologist Dr Sonia Reghunath says freckles, premature ageing of skin, and dark spots are common effects of UV exposure.

“People worry about tanning, heat burns, and rashes, but many still neglect basic precautions such as applying sunscreen, using sunglasses, or wearing appropriate clothing. As each summer gets hotter, these steps become vital,” she says.

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How heat affects mental well-being

According to the World Health Organization, heat is a major environmental hazard, increasing the risk of cardiovascular disease, respiratory illnesses, and even infectious disease transmission.

Now, as global temperatures continue to rise to alarming levels, experts are urging people to take precautions to protect both their physical and mental well-being.

While the physical effects of extreme heat — such as heat stress, dehydration, and cardiovascular strain — are well-documented, its impact on mental health is equally concerning. “Prolonged exposure to high temperatures can lead to heightened stress, irritability, anxiety, and cognitive difficulties. Heat can hamper decision-making and concentration as well,” explains psychiatrist Dr C J John.

“Furthermore, sleep disturbances caused by hot nights can worsen emotional health, affecting concentration, memory, and overall productivity. Heat stress can cause dizziness, nausea, headaches, and electrolyte imbalances. In extreme cases, it can escalate to seizures.”

Psychiatrist Dr Arun B Nair stresses on loss of sleep. “It affects everyone, from children to elders. It’s not just the day; nowadays, nights are also hotter,” he says.

“The lack of sleep leaves people exhausted throughout the day. It also affects memory, productivity, and the ability to learn.”

Dr Arun stresses that sleep is essential for the brain’s “waste-clearing process”, which occurs at night. “Without sufficient sleep, this process is hindered, leading to further complications,” he adds.Another concern, according to Dr Arun, is that mental health patients in remission tend to stop taking their medication during summer due to fatigue. “People presume the fatigue is caused by the medicine, while in reality, it is due to the heat and dehydration. This has both short- and long-term consequences,” he cautions.