When the thermometer loses 15 degrees in a short time, the body must also change rhythm. After a heatwave, a sudden return to normal or even low temperatures can cause fatigue, headaches, chills or dizziness. Dr Gérald Kierzek, emergency physician and Medical Director of True Medical, explains who is most affected by this change, the symptoms to watch out for and when it is necessary to consult.
From 40 to 25 degrees, why the body must adapt to this sudden change
Dr. Kierzek explains that this change is “generally not dangerous to a healthy person, but it can cause temporary physiological stress and mild symptoms“.
When the ambient temperature drops quickly, particularly after a storm or a change in air mass, the body must readjust its thermoregulation.
The emergency doctor describes several mechanisms: “cutaneous vasoconstriction, change in blood flow, adjustment of sweating and heart rate.“
This relative thermal shock is felt more when the difference exceeds 10 to 15°C in a short time. This is the case, for example, when going from a heatwave of 40°C to a temperature of 25°C accompanied by rain and wind.
The different symptoms you may observe
This transition can then be accompanied by mild and transient symptoms:
- Unusual fatigue or a feeling of fatigue may appear;
- Headaches or migraines;
- Dizziness or slight discomfort;
- Chills, a disproportionate feeling of cold;
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A dry and irritated throat;
- Temporary nausea and slight digestive problems may also occur.
In people sensitive to variations in pressure and humidity, joint or muscle pain can also be exacerbated.
The doctor also mentions the “weather sensitivity“, that is to say increased responsiveness to variations in temperature, humidity and atmospheric pressure.
Who is most likely to feel the effects of a sudden drop in temperature?
Not everyone reacts the same way to a sudden change from extreme heat to much cooler temperatures. The elderly and very young children are among the most sensitive groups, their thermoregulation being less effective and the feeling of thirst may be less well perceived.
People suffering from chronic illnesses should also be particularly attentive. But also people suffering from cardiovascular diseases, respiratory pathologies such as asthma or COPD, neurological diseases, diabetes or even kidney failure.
The risk may also be greater among people living in a precarious situation or in poorly insulated housing. A person who is already tired, dehydrated or coming out of a heatwave may also feel this transition more.
How to get through this transition period?
“It takes approximately 48 hours for the body to fully adapt to a change of more than 10°C.“
Hydrate well
Even when temperatures drop, Dr. Gérald Kierzek recommends continuing to drink regularly. The air can remain dry after a storm.
Adapt your diet
In terms of diet, he recommends split meals, with an intake of vitamins C and D as well as minerals such as magnesium and zinc, while favoring lukewarm or hot dishes when the temperature drops.
Choosing the right clothes
Layered clothing also makes it easy to add or remove layers depending on activity and time of day. The doctor recommends avoiding direct thermal shock: no very cold shower immediately after a heat stroke and no sudden exposure to very cold air caused by excessively strong air conditioning.
Finding restful sleep
Fatigue also invites you to slow down, take breaks and maintain sufficient quality sleep in order to support thermal regulation and immunity. For physical activity, Dr. Gérald Kierzek advises avoiding intense efforts during the 24 to 48 hours of transition, especially after a heatwave.
These signs should lead to seeking medical advice quickly.
In the event of discomfort or cardiovascular signs such as chest pain, severe palpitations, shortness of breath at rest or sudden worsening of a known heart disease, the doctor calls for a “prompt medical advice.“
Same recommendation in the presence of respiratory signs, such as respiratory distress, wheezing or sudden worsening of asthma or COPD.