Staying Hydrated in the Heat

As it gets hotter out, people are advised to limit their outdoor activities. Unfortunately, that is not always an option, especially for those who work outside. For those that must be outside, knowing the risk factors and knowing how to prevent them is key to keeping yourself protected.

Working outdoors in the heat can come with many risks. This can include heat exhaustion and heat stroke. High air temperatures, high humidity, direct sun exposure, physical exertion, dehydration, certain medical or physical conditions, not acclimatized and advanced age can all increase the risk of heat related illnesses.


Staying Hydrated

When we sweat, our 2.6 million sweat glands lose water and electrolytes, increasing the risk of dehydration. It is necessary to drink enough water to make up for this loss through sweating.

The CDC recommends that for moderate activity in moderate conditions, an outdoor worker should drink 1 cup of water every 15 to 20 minutes. It is important to drink water before becoming thirsty to remain hydrated. Sports drinks may taste better but may not replace the lost electrolytes as well as water can. When the conditions are hotter, a worker may need to drink even more than 1 cup every 15 minutes.

Keeping Cool

In addition to staying hydrated, it is important that workers take regular breaks in shaded or air conditioned areas to stay cool. When working outdoors, physical exertion can increase the core body temperature, making it harder to cool down.

Using reflective clothing, water dampened cotton clothing and cooking vests can help keep workers cooler in extreme heat.

Source: “Keeping Workers Hydrated and Cool Despite the Heat”, NIOSH Science Blog,