Three people have died in heat-related incidents at Grand Canyon National Park over the last week, according to a news release from the National Park Service (NPS).

According to the NPS, park rangers responded to two separate heat-related incidents on June 12 and June 16, with three people dying. One June 12, a 72-year-old man succumbed to symptoms of heat-related illness on the South Kaibab Trail. On June 16, a 67-year-old man and a 68-year-old woman also seem to have died of heat-related illness on the North Kaibab Trail. The investigation is still ongoing.

The NPS said that although there were rapid responses and there was aerial support, all three people were found deceased when responders arrived. All three individuals were taken to the Coconino County Medical Examiner office. There is no additional information that has been released at this time.

The NPS also said that hiking the Grand Canyon can be challenging for anyone, “especially during the heat of summer.” Summer temperatures have reached dangerous levels in the Inner Canyon, where temperatures can exceed 109 degrees in the shade during midday hours, according to the NPS. This creates conditions that can “quickly overwhelm hikers during the hottest parts of the day.”

Because of these conditions, the NPS encourages visitors to stay off Inner Canyon trails from 10 a.m. to 4 p.m.

Find more information about visiting the Grand Canyon in the summer here.

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