Working in hot environments and/or prolonged exertion can raise the body’s temperature, resulting in heat stress that may lead to heat exhaustion, heat cramps, heat rashes, and heat stroke.

According to NIOSH, heat stroke is the most severe form of heat-related illness and can be fatal if not quickly treated.

The symptoms of heat stroke include a change in mental status that can range from confusion or bizarre behavior to seizures or loss of consciousness.

Heat stress may be avoided by taking the following steps:

• Wear light-colored, loose-fitting, breathable clothing, such as cotton. Avoid
  non-breathing synthetic clothing, and always wear a hat.
• Be aware that protective clothing or personal protective equipment (PPE) may increase the risk of heat stress.
• Schedule heavy work during the coolest parts of the work day.
• No matter how tempted you are to skip them, take more breaks in extreme heat and
  humidity. Find shade or an air-conditioned space when possible to cool off.
• Acclimatize workers by exposing them for progressively longer periods to hot work
  environments gradually or bring in relief workers for physically demanding jobs.
• Use the buddy system to keep a watchful eye on your co-worker. Recognize the
  warning signs for heat stress and make sure that they move to a cool area immediately.

Drink water and low-sugar, electrolyte replacing drinks frequently, even if you are not thirsty. Consume approximately 1 cup every 15 to 20 minutes. By the time you become thirsty, you are already dehydrated.