Ice Water and AC Are No Cure: Doctor Warns of Heart Risk
Cooling down too fast in the heat strains the heart and brain. Dr Sasa Milicevic explains why ice water and cold air conditioning are not the answer, and how to cool off safely.
- Sudden temperature swings narrow the blood vessels, which strains the heart and brain, warns Dr Sasa Milicevic.
- The first 2 glasses of water after being in the heat should be at a moderate temperature, not ice cold.
- Constantly moving from AC set to 17 degrees into the hot outdoor air is a shock to the body.
- Jumping into cold water can be dangerous because of the abrupt narrowing of blood vessels.
Does ice water really cool you down when it is sweltering? Not the way you think, and on a scorching day it can even be dangerous. Dr Sasa Milicevic warns that sudden differences in temperature cause the blood vessels to constrict, which puts extra strain on the heart and brain.
The mechanism is simple. When a hot body suddenly meets something cold, the blood vessels contract to conserve heat. That reflex is useful in winter, but in summer, when the body is already under pressure from high temperatures, the sudden narrowing of vessels piles more load onto the heart. That is why doctors advise cooling down gradually rather than in one sharp hit.
Why is ice water not the best choice in the heat?
Gulping down ice water all at once is a stress on the stomach and the esophagus. A body that is hot inside suddenly takes a cold hit, and instead of relief it feels a cramp. Dr Milicevic advises that the first two glasses after sun exposure be at a moderate temperature, just cool enough to refresh you without shocking the system.
There is one tip that sounds odd to many people. Tea quenches thirst very well, even when it is hot outside. A warm or lukewarm drink does not push the body into an abrupt reaction, and it replaces fluids at the same time. Try an unsweetened herbal tea cooled to room temperature instead of ice water straight from the fridge, the difference in how you feel half an hour later can be noticeable.
The same goes for air conditioning. A cold, air-conditioned room feels like salvation, but constantly stepping from air set to 17 degrees into the heat outside taxes the body. Each of those transitions is a small shock to the blood vessels. Our recommendation is not to set the AC to an extremely low temperature, but to a difference of about six to eight degrees from the outdoor air, which is enough to feel pleasant without a sharp contrast.
How do you cool down without taking a risk?
The most dangerous move is jumping into cold water when you are overheated. Dr Milicevic warns that the abrupt narrowing of blood vessels in that moment can even be fatal, especially for people who already have heart trouble. If you are heading to a river, a lake or a pool, get in gradually and let your body adjust to the temperature before you go under.
Here are a few practical steps you can use today. Before you head from a cold room into the heat, pause for a minute in the shade so the body can adjust. Drink water in smaller sips at a moderate temperature, not ice cold and not in one go. Swap a cold shower for a lukewarm one, which cools you without the shock. And most important, give the body time to adapt slowly, because the sudden changes are what really wear it out.
It comes down to rhythm, not temperature. The body likes things gradual, and summer is precisely the season when that is easiest to forget. So how do you cool off on the hottest days, all at once or slowly?
