• Staying hydrated is one of the best ways to avoid heat stress.Jacqueline Veissid/Photodisc/Getty Images
  
  Heat stress is a risk for anyone who enjoys outdoor activities in the warm, summer months. It is a result of the body being unable to cool itself down to a normal temperature during activities. It can also strike people who work in conditions where machinery emits heat and raises temperatures indoors. The symptoms can be mild, such as a rash or cramps, or deadly, as in heatstroke. Knowing how to recognize the causes is the best way to prevent heat stress.
  
  

Dehydration

• Sweating is a response to you overheating in an attempt to cool you off. The optimum body temperature is 37 Celsius. Sweating is responsible for 70 percent to 80 percent of the body's heat regulation, according to the MBF website. Not drinking enough water or other fluids is the main cause of dehydration. When you're dehydrated, you don't sweat and your internal temperature can rise to a dangerous level. High humidity prevents the body from sweating properly, so it is important to use extra caution then in humid conditions.
  
  

Improper Airflow

• Some people work in confined areas where the air ventilation is minimal, as in a factory or bakery. If the conditions are hot as well, such as in a mine, boiler room or fighting a fire in a building, the chances of heat stress increase. Protective clothing and safety equipment, such as bullet-proof vests or hard hats, increase the heat in your body.
  
  

Sun Exposure

• A large amount of sun exposure, particularly if you are not used to it, can cause heat stress. The sun is at its hottest between the hours of 11 a.m. and 3 p.m., so stay out of the heat during this part of the day. If you must work or play outdoors during these hours, drink plenty of water, stay in the shade and rest when you can.
  
  

Crowded Areas

• In many events, such as concerts, sporting events or dances, the conditions are hot and crowded. This presents a situation where a person might experience heat stress and its health-related problems.
  
  

Improper Clothing

• During the summer, wear clothing that breathes, such as cotton or linen fabrics. Avoid synthetic clothing because it does not allow ventilation for your skin, thus increasing how hot your body is. Tight-fitting clothes and darker colors can also make you hotter.