On a hot and humid day, aside from an iced beverage or a cool breeze, few things are more refreshing than a cold shower, but it turns out that those cold showers may be causing more harm than good.
An expert told The Mirror that during a heatwave, you should actually take a hot bath to cool down. They explained, "Taking a cold shower or bath can actually be counterproductive as when our body is submerged in extremely cold conditions it tries to regulate our core temperature. This means you could actually feel hotter than you did before you tried to cool down." They went on to say, "By taking a hot bath we are able to drop our body temperature as it stimulates our body's thermoregulatory system. This increases the circulation of blood throughout our body and results in the removal of body heat and therefore a decreased body temperature."
The expert isn't alone in their suggestion - the National Sleep Foundation backs it as well, advising in one guide that "when the room temperature is very high," it is better to take "hot showers and hot baths." As for the reason a sleep group is making the suggestion, that's because your body temperature drops when you sleep, and a hot bath on a hot day will drop your temperature and "may help you feel sleepy," and "the bath can help you relax," all of which will lead to better rest.