Taking hot bath before bed 'can help you sleep better' in heatwave

You might be accustomed to cooling down with a quick cold shower or grabbing a chilled drink from the fridge to beat the summer heat. However, when temperatures soar to heatwave levels, it may seem counterintuitive to take a hot bath - but experts insist there's a science behind this seemingly odd advice.

Healthline cites a study which found that having a hot bath about 90 minutes before hitting the sack could aid in falling asleep faster. It may seem a bit backwards to dip into hot water when it's sweltering outside, but scientific evidence supports this theory.

The research was spearheaded by Shahab Haghayegh, a PhD candidate in the department of biomedical engineering at The University of Texas at Austin. The team carried out a systematic data analysis assessing research connecting bathing, water temperature, and sleep quality.

They scrutinised 5,322 studies and utilised roughly a dozen with robust methodologies to arrive at their conclusions. Their findings indicate that taking a bath one to two hours - ideally, 90 minutes - before bedtime in water at 104 to 109F (40 to 43C) can assist individuals in achieving optimal sleep quality.

Bathing at that specific time and temperature could help you drift off to sleep an average of 10 minutes quicker than usual, reports the Mirror.

Another study published in the Sleep Medical Reviews journal revealed that our brain's circadian clock, which regulates 24-hour patterns of sleep and wakefulness, also controls both sleep and body core temperature. It's during sleep that our body temperature is at its lowest, and a drop in body temperature after a bath can help prepare us for sleep.

However, taking a cool bath or shower before bed could have the opposite effect, leading to a restless night. This research is supported by the Sleep Foundation, which found that cold showers might not improve sleep due to the stimulating properties of cold water that increase levels of cortisol and norepinephrine in the body.

Cortisol plays a role in enhancing alertness levels, and typically, cortisol levels in the body decrease in preparation for sleep. In one study, participants likened the energy boost from a cold shower to the effects of consuming caffeine.