Warning: This article contains images of second-degree burns. 

Parents are being warned about the dangers of water within hosepipes heating up in the sun – and coming out vastly hotter than expected.

With temperatures of up to 37 degrees expected this week, a blast of ice-cold water from a hose may seem appealing, but that might not be what you get.

Images are being circulated on Facebook of a child from Arizona who is said to have suffered second-degree burns after being sprayed with a hose, the contents of which had heated up in the sun.

His mum reportedly assumed cold water would come out, so interpreted his scream as a reaction to being sprayed in general, rather than to being burned, according to Heart. The toddler ended up with second-degree burns over 30% of his body, but was lucky to escape permanent scarring.

[Read More: 7 Cooling After Sun Products To Take The Sting Out Of Your Sunburn]

The images were shared by a woman named Stacey from Daisy First Aid Redhill & Croydon, who do family first aid lessons.

She also shared a warning from the firefighters who helped the toddler at the time: “A garden hose exposed to direct sunlight during summer can heat the water inside the hose (not flowing) to 130-140 degrees fahrenheit (54-60 celsius) which can cause burns, especially to children and animals.”

Spraying people with hoses can be fun, and eternally tempting in this kind of weather – so running the hose for a little while before aiming it at anyone and checking the temperature yourself will make sure everyone stays safe in the sun.