Heatstroke and overheating are triggered by too high body temperature. Temperature rises due to excessive heat supply and low heat dissipation. The first symptoms are thirst, headache and weakness. Developing the condition itself affects both the brain and the heart's function. Cooling and fluid can improve the condition. In case of heatstroke contact your doctor immediately.
Heatstroke and overheating are due to that the heat supply of the body is greater than the heat dissipation. Hard physical work and direct radiation from the sun cause increased heat in the body. With high humidity it is difficult for the body to get rid of the heat. Too little fluid worsens the condition.
The combination of hard physical work, high temperatures (above 33oC), high humidity (over 60%), fluid deficiency and direct heat radiation from the sun or from machines can therefore lead to overheating and heatstroke.
Overheating is felt by increased thirst, headache, dizziness and weakness. The skin is hot, red and moist. The temperature is above 38oC but below 40oC.
Overheating can develop into heat stroke.
Heatstroke is a life-threatening condition in which the body's temperature reaches over 40oC. Heatstroke affects both the heart and the brain. Consciousness is affected, and you get rubbish, confused and hallucinated (seeing visions). There may be paralysis, balance disturbances, double vision and unclear speech. The breathing gets fast. The skin is pale, dry and warm. The condition can develop into shock, where you become unconscious.