Less infant shuteye in searing heat

By the time she had her third child, Reshma Kamble was sure she was no longer in for any surprises when it came to raising kids. But she started to notice that there was something off about her youngest’s sleeping habits – or lack thereof.   

“I knew neonates wake up anytime during the night, but something was different about Harshvardhan,” says Kamble about her now 4-month-old son. 

When she witnessed him getting restless and trying to sleep for the first time, Kamble fed her son gripe water (an herbal supplement), assuming things would get better. “He did sleep for a few minutes,” she says, “and started crying again.” 

She then thought Harshvardhan was experiencing a stomachache. But that also turned out to be incorrect. “For a few days, he didn’t sleep the entire night,” says Kamble.

Confused, she began observing Harshvardhan closely. “I kept noting the time I breastfed him,” she recounts, “if he was allergic to something around, or if anything was wrong with the surroundings.” 

It took a month before she figured out what the problem was. Says Kamble: “Whenever it got too hot at night, Harshvardhan would wake up and start crying. As soon as I brought a table fan nearby, he felt better.”  

Kamble and her family are among the less than 1,100 residents in the remote Kerle village in Maharashtra state in western India. While India is known as having a hot climate, average summer temperatures across the vast country vary, with the northern Himalayan region having the coldest, ranging from 5 to 25 degrees Celsius. Thermometers in the Indo-Gangetic Plain and the southern peninsula have been known to read 40 degrees Celsius during the summer months. Maharashtra, which is part of the coastal region, has temperatures that range between 25 to 35 degrees Celsius. Yet while it is humid all year round, Kamble says that “this place never got so hot,” even during summer. 

That is, until the last few years, and along with the rest of India. Government data shared recently in Parliament in fact reveal that between January and June this year, India lost 264 people to heat wave-related ailments. 

Like the elderly, children and infants are especially sensitive to extreme temperatures. Currently, 559 million children globally are exposed to more frequent heat waves. For infants, exposure to such leads to, among other things, sleepless nights, which in turn have a significant impact on their development. Says Ranjana Gavade, a community healthcare veteran for 15 years: “Sleep problems during infancy can cause several issues.”

Essential to growth

Members of the American Academy of Sleep Medicine recommend infants between the ages of four to 12 months to “sleep 12 to 16 hours per 24 hours (including naps) on a regular basis to promote optimal health.” A research paper published in Scientific Reports this June noted, “Sleep is fundamental to healthy growth and development. Getting less than the recommended amount of nightly sleep in infancy increases the likelihood of being overweight in preschool, is associated with emotional and behavioral problems in early childhood, and is positively associated with poorer language development and problem-solving skills.”

“A hallmark accomplishment of infancy is the maturation of sleep, as reflected by a decrease in fragmentation, the establishment of a circadian rhythm, and, ultimately, sleeping through the night,” it also said. “Unpredictable interruptions to this process could potentially impact the establishment of mature biological functioning. This, in turn, could have cascading effects on later development. For example, sleep fragmentation at 10 months old was related to poor performance on a standardized assessment of cognitive development. Similarly, total sleep time at 18 months old was related to executive functioning at two years old. Likewise, higher sleep efficiency at one year of age predicted executive functioning (but not general cognition) at four years.”

The paper was based on the sleeping patterns of 413 infants in greater London in the United Kingdom during the summer of 2022. It observed, “Sleep was not impacted when temperatures stayed below 31.11 degrees Celsius but was negatively impacted when temperatures reached over 37.8 degrees Celsius. Compared to non-heat wave nights, infants had less total sleep, less efficient sleep, took longer to fall asleep, had more fragmented sleep, and parents’ visits were more frequent during the night.”

In India, research found that the frequency of concurrent hot day and hot night events has significantly increased. By the end of the 21st century, it is poised to grow twelvefold from the current level, highlighting the surmounting danger for infants and children. 

Globally, one in three children is exposed to higher temperatures. In South Asia, however, that ratio is three in four children. UNICEF says that 460 million (76 percent) children in South Asia are exposed to extreme temperatures, with more than 83 days of the year exceeding 35 degrees Celsius. In southern Maharashtra, where Kamble’s village is, the temperatures were already going over 40 degrees Celsius in early May.

In a 2022 paper on the effects of high and low ambient temperatures on infants, researchers pointed out that several factors affect the thermoregulation – “the control of internal body temperature” – in infants.  

“Infants have immature thermoregulatory mechanisms, a higher metabolic rate (more energy expenditure), and a higher sweating threshold,” wrote the researchers. “Additionally, infants have a smaller blood volume and a higher heart rate, which will affect the response of the heart and blood vessels to extreme temperatures. Anatomically, infants, and especially preterm neonates, have a higher body surface to volume ratio which increases exposure to temperature.”

The researchers did not mention sleep disorders. They did note, though, that their review of literature indicated that “higher ambient temperatures and heat waves were associated with an increased risk of all-cause infant mortality, all-cause hospital admissions, and HFDM (Hand, Foot, and Mouth Disease) incidence.”

Compounding worries

Before heat waves made it difficult for infants to sleep, several other factors were already making Indian children sleep-deprived. For those between the ages of one and 12, research done on 650 children in Puducherry town in southern India found that “increased screen time and reduced physical activities in children contribute to poor sleep habits and sleep problems.” 

The parents’ socioeconomic status, employment, and education can also influence their children’s sleep patterns. A study conducted between November 2018 and June 2019 on children’s sleep disorders in Chennai in southern India said, “Nonstandard irregular work patterns among parents were found to have negative influences on the child’s cognitive outcome and sleep, which was prevalent more in single-parent and low-income families.”

Heat causing sleeplessness in infants was probably far from community healthcare worker Gavade’s mind when she received a call at 1:00 in the morning months ago. The caller was Hasina Hajukhan, who was beside herself with worry over how her twin babies – a boy and a girl – were not able to sleep.  

Gavade has been visiting Hajukhan’s twins frequently since she received that early-morning call.  

Hajukhan’s family has spent over INR 5,000 (US$60) on medicines and doctor fees, but so far the 4-month-old twins aren’t getting the sleep they sorely need. Their grandmother Baimabhi Maldar reports, “They just don’t sleep even during the night and the day.” 

“I’ve looked after hundreds of infants,” confesses Gavade, “but never faced this issue until now.” 

Hajukhan, a first-time mother at 28, now spends most of the day worrying about her children’s sleep schedule. “I, too, had a tough time sleeping during the heat waves,” she says. “Even I couldn’t sleep in the night.”

Hajukhan fears that the heat can lead to neurological dysfunction, jaundice, and dehydration in her babies. After all, infants have been observed to breastfeed for shorter periods during the hottest days, compared to periods when the weather is chilly. Hajukhan is experiencing that firsthand. She says, “My twins are underweight, and the doctor keeps saying that less breastfeeding is making it difficult for the twins.” 

Gavade is also worried. She comments, “This is risky because infants don’t get enough nutrients in such cases.” 

The 40-year-old healthcare worker at first thought that Hajukhan’s breastfeeding problem was a rarity. But as her village, Ganeshwadi, in Maharashtra’s Kolhapur district, started experiencing heat waves, the problem was revealed to be widespread. According to Gavade, she was soon hearing the same concern from several other parents. 

Elsewhere, mothers have been reporting similar problems. Dr. Milind Kolap, a community health officer posted in Maharashtra’s Shirdhon village, says, “During extreme heat, I’ve seen several cases of parents talking about problems with breastfeeding.” Kolap has been advising parents that proper ventilation is required, especially during heat waves.

The oppressive heat, however, can affect infants even before they are born. Says Gavade: “This year, during pregnancy, many women suffered a lot because of the unbearable heat. This even led to multiple cases of premature birth with underweight newborns, which made them vulnerable to diseases.” ◉