Heat syncope symptoms generally occur in people who must stand upright and remain still for long periods of time in a hot environment. They can also occur in people who exercise vigorously in the heat. Heat syncope is considered a type of heat-related illness, and most medical authorities differentiate it from other heat-related illnesses such as heat stroke, heat illness, and heat exhaustion. Common heat syncope symptoms usually include sudden dizziness and loss of consciousness.
Heat syncope may be one of the less severe heat-related illnesses. It generally occurs in people who have remained standing upright, in a relatively stationary position, in hot temperatures. for a prolonged period of time. Heat syncope may be related to problems with blood circulation that may occur due to the effects of heat on the vascular system.
Hot temperatures can cause blood vessels to dilate, or become wider. In people who remain standing motionless in hot temperatures, blood can drain into the legs and feet, leading to a lack of oxygen in the brain. Heat syncope can also afflict people who exercise vigorously in the heat, especially if they stop moving and remain still immediately after vigorous exercise in the heat.
The most common and recognizable heat syncope symptoms generally include a feeling of vertigo, or dizziness, followed by loss of consciousness. Heat syncope symptoms can also include paleness and clamminess of the skin, rapid heart rate and weak pulse, though internal body temperature typically remains within the normal range. Medical attention is generally advised for those suffering heat syncope symptoms, but most people recover quickly from this heat-related illness. Often, the recovery process begins while the unconscious person is the prone position, since this position can allow blood to circulation more freely through the body, bringing oxygen back to the brain.
There are a number of other heat-related illnesses that can strike persons exposed to hot and humid environments. Common heat-related conditions can include heat rash, which typically occurs after heavy perspiration in heat and humidity. Those who engage in strenuous physical activity in the heat may suffer from heat-related muscle cramps. When the body begins to overheat, heat exhaustion can occur, causing nausea, sweating, thirst, dizziness, and giddiness. Heat stroke, a potentially fatal heat-related illness, occurs most often when the body becomes so hot that the internal body temperature begins to surpass normal levels.