Ouch!

Julie Nisbet, 34, noticed strange orange balls on her legs hours later after running 69 miles along the Hadrian Wall, in England, in the scorching heat. The balls were increasing in size per minute and filled with puss, leaving Nisbet in excruciating pain.

The mother of two was running from coast to coast, but after 21 hours participating in the marathon, she noticed orange balls starting to appear on her legs.

Nisbet immediately sought medical attention, but still suffers from the agonizing blisters a week later.

Her family and friends did not believe blisters could develop into large, puss-filled sacks from sunburn, despite Nisbet taking every precaution to prevent.

"I was wearing sun cream at the start of the race but hadn't reapplied - sweat and water had pretty much got rid of what I had on the backs of my legs," said Nisbet, explaining the temperature at its hottest was about 30 degrees Celsius."

To lower the risk of blisters and other side effects from sunscreen lotion, discuss different types or brands with your doctor before engaging in physical activity outdoors.