What are the symptoms of heatstroke and summer cold (heat-induced cold)?

Heat-related cold refers to summer cold. Generally, heatstroke presents symptoms such as dizziness, headache, excessive sweating, thirst, and weakness in the limbs. A summer cold may cause symptoms including dry mouth and throat, body fatigue, nasal congestion, thick nasal discharge, and irritability. Specific analyses are as follows:

I. Heatstroke

1. Dizziness
Under high temperatures, people typically sweat heavily to dissipate heat. This can lead to excessive loss of body fluids, causing dehydration. Dehydration reduces blood volume, affecting blood flow to the brain. When cerebral blood supply decreases, it may result in dizziness.

2. Headache
During heatstroke, elevated body temperature causes blood vessel dilation, including cerebral vessels. The expansion of brain blood vessels may increase cerebral blood flow, potentially leading to headaches.

3. Excessive Sweating
During heatstroke, the body attempts to lower its temperature through sweating. Significant fluid loss from sweating can reduce body water content, resulting in dehydration. Reduced blood volume forces the heart to work harder to pump blood to meet bodily needs, increasing cardiac load and contributing to greater fatigue.

4. Thirst
Due to substantial fluid loss through sweating, individuals suffering from heatstroke often feel thirsty. Thirst is a natural physiological response aimed at restoring the body's fluid balance.

5. Weakness in Limbs
During heatstroke, the body may redirect more blood flow to the skin surface for cooling, reducing circulation to other areas, which may lead to limb weakness. Additionally, dehydration and electrolyte imbalances can impair muscle function, causing a sensation of weakness in the limbs.

II. Summer Cold

1. Dry Mouth and Throat
One reason summer cold causes dry mouth and throat is increased body temperature and sweating. In hot conditions, large amounts of bodily fluids are lost, including saliva in the mouth. Moreover, sore throat or inflammation—a common symptom of summer cold—can also contribute to a dry sensation.

2. Body Fatigue
Summer colds are caused by viruses. After infection, the immune system activates to fight the virus, which may lead to general fatigue and weakness. In addition, sweating and dehydration can further contribute to feelings of tiredness.

3. Nasal Congestion
Summer colds are usually caused by various types of viruses that infect the upper respiratory tract, including the nose and throat. The infection triggers inflammation, leading to nasal mucosal congestion, which results in nasal blockage and thick nasal discharge.

4. Purulent Nasal Discharge
Viral infection induces inflammation of the nasal mucosa. This inflammatory response causes dilation and congestion of mucosal blood vessels, along with increased secretion from mucosal cells, resulting in purulent (thick, often yellowish) nasal discharge.

5. Irritability
Cold symptoms—especially discomforts like dry mouth, nasal congestion, and thick nasal discharge—can make a person feel uneasy and irritable. Furthermore, hot weather itself may cause discomfort, and when combined with symptoms of a summer cold, this may intensify feelings of irritability.

If heatstroke occurs, it is recommended to use medications such as Huoxiang Zhengqi Water or Qing Shu Yi Qi Wan under medical guidance, while moving away from high-temperature environments. For summer colds, patients may take medications such as Yin Qiao San or Feng Re Gan Mao Ke Li under a doctor’s supervision, along with adequate rest.