Rising night temperatures could affect deep sleep and recovery
Hyderabad: Hyderabad’s summer may not bring much relief after sunset this year, and doctors say the impact could be felt most at night. The India Meteorological Department, in its hot weather season outlook for March to May, with nights warmer than usual as daytime heat builds.
Sleep specialists say this could directly affect how the body rests after a hard day’s work. “Sleep is regulated by the body’s core temperature cycle. For the brain to enter deeper stages of sleep, the body needs to cool slightly. When ambient temperatures remain high, this cooling process is delayed,” explained Dr Neerav Chandra, specialist in interventional pulmonology and sleep medicine.
“You may fall asleep, but the structure of sleep changes. There is less time spent in deep sleep and REM sleep, which are essential for physical and mental recovery,” Dr Chandra said, referring to the rapid eye movement segment of sleep.
Doctors say this problem is more visible in cities like Hyderabad, where heat stays trapped even after sunset. Extreme heat places significant strain on the body’s ability to downshift for the night, said Dr Devi Vinaya, general physician in Kondapur.
“We often see patients struggling with heat-induced insomnia, where the body cannot reach the thermal neutral zone required for deep, restorative sleep. In urban centres, the problem is compounded, buildings radiate heat long after the sun sets, preventing the natural cooling of the environment,” Dr Vinaya said
She said the body could also show warning signs with regard to temperature stress. “If you find yourself waking up with a headache or tachycardia, your body is likely failing to thermoregulate during the night, signalling a transition from simple discomfort to early heat exhaustion.”
Doctors explained how sleep begins at night. “Body temperature decreases naturally at night towards 10 pm and helps release melatonin that induces sleep. If the environment is hot, this release gets interrupted and causes restlessness,” said Dr Guru N. Reddy, senior gastroenterologist.
Room temperature played an important role in sleep quality and that much heat can degrade melatonin faster leading to delayed onset of sleep and fragmented sleep, they said.
“In Indian settings, maintaining the AC temperature at about 24º Centigrade can give optimal room temperature for pleasant sleep. Use of fan along with AC circulates cold air faster, creates wind chill effect and reduces electricity consumption,” said Dr Pradeep Simha Karur, senior consultant pulmonologist and sleep physician.
Doctors said how cooling is managed also matters. When nights stay hot, the body doesn’t cool down the way it should before sleep. “Cooling down of the body is important, without it, people take longer to fall asleep, keep waking up, and don’t get deep, restful sleep. Ideally, the room should be slightly cool., avoid direct cold air, and ensure proper ventilation,” said Dr Chaitanya Challa, senior consultant in general medicine.
Some of the simple ways to cope is a combination of AC and fan helps reduce humidity. “If cooling is not available, even simple methods like sleeping under a damp sheet can help,” Dr Guru Reddy said and added that the effects of poor sleep may not be immediate but can build over time, affecting energy levels, concentration and overall health.
