More than 100 people were treated for heat-related illness at a Colorado airshow on Saturday, with attendees describing a lack of shade and free water on festival grounds as temperatures soared to 96F (36C) highs.

The Colorado Springs fire department said those who fell ill at the Pike’s Peak regional airshow suffered conditions such as dehydration, heat exhaustion and heat stroke, according to KRDO.

Five people were taken to hospital. Another hundred reportedly sought help in a triage tent where several were given IV fluids on site.

The airshow ran out of free water, authorities said, but noted that attendees could fill their bottles with water at the medical tent and that vendors also had water for sale.