how they differ and why they don’t let you sleep

It is often said that any time in the past was better. Normally this phrase is the fruit of our tendency to idealize what has already happened. However, with The heat and hot nights are beginning to be an indisputable reality.. If we think of our past summer nights, we remember the tropical nights, in which the temperature does not drop below 20ºCas something specific. In the case of Spain, at least, they were isolated nights in which sleeping was a challenge. Now, however, they have not only become a norm that makes us live hugging the fanbut we have unlocked two other types of nights: equatorial and infernal.

The name of the latter gives what it promises. Because of global warmingour nights have become hell; which, unfortunately for us, has only just begun. This affects our rest and, as a consequence, our performance during the day and our long-term health. It is no small feat, so it is worth looking for methods to sleep despite the high nighttime temperatures. Of course, before seeing what those methods may be, it is important to start at the beginning and learn what each type of night consists of.

The night thermometer: difference between tropical, equatorial and infernal night

As we have seen, when we talk about hot nights, there are three different types.

• Tropical night: It is what we were more or less used to, although not with the frequency of today. It occurs when temperatures do not drop below 20ºC throughout the night.
• Equatorial (or torrid) night: In this case, the mercury does not drop below 25ºC. It may not seem like much, but 5ºC is very noticeable. Normally these high night temperatures are reached by heating the sea water, heat island effect in cities or hot, dry winds.
• hellish night: The name delivers what it promises. Temperatures do not drop below 30ºC between dusk and dawn, so rest is much more complicated and the effects of heat even more dangerous than during the day in some cases.

Why is it physically impossible to sleep in these temperatures?

Our dream is governed by circadian cycles. These are 24-hour cycles with which many of our physiological functions are regulated. In the case of sleep, we sleep once a day, usually during the night. Therefore, when our brain detects that it has gotten dark, it begins to release melatonin, the hormone that helps us fall asleep. On the other hand, as daylight sets in, the release of this hormone is inhibited.

But melatonin doesn’t tell us to close our eyes and put our brains in rest mode until the next day. This sleep stimulation takes place on many levels. For example, in order for us to sleep, our body temperature must drop a little. It is something that occurs naturally, thanks precisely to that release of melatonin. But of course, if the ambient temperature is very high, it is too complicated to maintain that ideal temperature for rest.

This is why we have such a hard time sleeping on hot nights. The entire process is affected, although the most susceptible is REM sleepessential for a good rest.

What happens to your body when you try to sleep at more than 25ºC?

We have seen that the brain detects when it is day and night, but how does it do it? There are actually several factors. The most intuitive is the entry of light through the retina. If there is light, it is interpreted as daytime and when it decreases it is associated with night. This is the reason why having rooms that are too lit at night, especially with blue light, makes it difficult for us to fall asleep.

However, light is not the only indicator of day and night. The brain is also guided by temperatureswhich normally rise during the day and descend at night. It is not usual for the temperature to be above 25ºC at night. That’s why, circadian rhythms get out of whack and cannot fall asleep properly. If melatonin were released in adequate quantities, it would lower the temperature even further, but when it is very hot not enough is released, so everything becomes a vicious circle.

In addition, the hypothalamus, which is our first center for regulating body temperature, continues to work at full capacity. It must continue working so that our body does not get too hot, so remains overactivated and we cannot rest. As you see, everything leads to the same thing. With the high night temperatures we cannot rest.

The ideal temperature to fall asleep according to science

With everything we have seen above, it is clear that there is an ideal temperature to fall asleep. If it is too high, circadian cycles become unbalanced, while excessive cold does not help us sleep either. That’s why, the sleep foundations recommendation is maintain the temperature of the rooms in which we sleep between 15.6ºC and 20ºC. The open window on hot nights does not help, since even tropical nights, the least severe, rise above that range.

The map of sleepless nights in Spain: the most affected areas

The areas most affected by hot nights are mainly the Mediterranean regions, the Guadalquivir basin, the community of Madrid and Extremadura. Also are becoming increasingly common in the Canary Islandswhere an increase in hellish nights is even beginning to be detected.

The Mediterranean and the Guadalquivir Valley: the “hot spots” of summer

In the Mediterranean highlights the case of the hellish nights in the province of Almeríawhere in June 2026 there have been four consecutive nights with temperatures above 30ºC.

In the Guadalquivir Valley and regions close to its basin they are not far behind. Although there they are standing out more due to the maximum temperatures than the minimum ones, so far this summer tropical nights have already been recorded in places like Écija, belonging to the province of Seville. In any case, its particular hell occurs during the day, with maximum temperatures well above 40ºC.

What can you do to sleep better at night?

High night temperatures make it difficult for us to fall asleep, but it is true that There are some tricks we can resort to.

To start, we must keep our rooms as cold as possible. That doesn’t mean we should turn the air conditioning on full. Not the best sleeping companion. What we can do is close windows and blinds during the dayso that the sun does not overheat the room. The ideal would be to open them later at night, although that option is discarded with heat waves and the hot nights we’re talking about. If the temperature helps, creating a draft by opening the window and door would be the perfect option.

It is also recommended take a warm shower before going to sleep. Although the intuitive thing would be to take a cold shower, the body can invest a lot of energy trying to compensate for this drop in temperature, so we would end up being even hotter.

On the other hand, before going to sleep we should avoid drinking alcohol, doing intense exercise or eating heavy meals. All of this increases the temperature, which is precisely what we want to avoid. And, to top it all off, wetting ourselves slightly before going to bed is an option that will at least relieve us in the first phases of sleep.

It would be great to not have tropical nights outside the window. But, if there is no other option, we will have to resort to these tricks to get the best sleep possible. What a remedy.

Image |Magnific

In Xataka | ENT doctors agree: “Sleeping with air conditioning forces the nose to work excessively”