During hot weather, in crowded places or while standing in line for extended periods, many people experience sudden weakness, dizziness, trembling or a general feeling of being unwell. Although these symptoms may appear to be simply the result of “heat exhaustion,” blood sugar fluctuations or metabolic abnormalities may also be involved.
Hot weather can significantly affect how the body functions. High temperatures cause blood vessels to dilate, which may lower blood pressure, while sweating and fluid loss increase. As a result, blood flow to the brain and muscles may be affected, potentially causing fatigue, weakness or a feeling of unsteadiness. At the same time, changes in the body’s energy requirements and hormonal regulation can make blood glucose levels more sensitive to fluctuations.
The symptoms of blood sugar fluctuations can often resemble the feeling of becoming unwell in the heat. Trembling, sweating, sudden hunger, a rapid heartbeat, difficulty concentrating or even feeling faint may occur. These symptoms may be particularly common when someone eats irregularly, does not drink enough fluids, consumes large amounts of caffeine or spends a prolonged period in a crowded, poorly ventilated environment.
Stress can further contribute to the problem. In crowded environments, while travelling or during periods of intense heat, the body releases stress hormones such as cortisol and adrenaline, which can affect blood glucose regulation. In some people, this may lead to a rapid rise in blood glucose followed by a sudden drop, resulting in renewed weakness or discomfort. In people with insulin resistance, the body’s ability to adapt may be slower and less stable, which can make these symptoms more pronounced.
If episodes of feeling unwell occur regularly, particularly after skipping meals or during hot or stressful situations, laboratory testing may be advisable.
A 3-point oral glucose tolerance test with glucose and insulin measurements can help identify insulin resistance or previously undetected abnormalities in carbohydrate metabolism. HbA1c provides information about average blood glucose levels over the previous three months, while an electrolyte panel and cortisol testing can provide additional information about the body’s fluid and hormonal balance.
Frequently Asked Questions
Can hot weather itself cause an episode of feeling unwell?
Yes. Heat places additional strain on the cardiovascular system and increases fluid loss, which can lead to dizziness or weakness.
How can I tell whether blood sugar fluctuations may also be involved?
If trembling, sudden hunger, sweating or recurrent weakness occurs, it may be worth discussing the symptoms with a healthcare professional and considering appropriate laboratory testing.
What is a 3-point glucose tolerance test?
It is a laboratory test in which blood glucose and insulin levels are measured at three different time points after consuming a glucose solution.
When is insulin resistance testing recommended?
Testing may be considered in cases of recurrent episodes of feeling unwell, persistent fatigue, significant fluctuations in appetite or feeling unwell after meals.