Heatstroke is a serious medical condition that can develop quickly in hot conditions if the body is unable to cool down. The risk of heatstroke and deaths from it have been increasing in recent years. To prevent heatstroke, it is important to stay out of direct heat, keep the body cool by drinking cold fluids and taking cool showers or baths, and keep indoor environments cool with closed windows and curtains. Heatstroke requires emergency medical treatment if symptoms develop.