The warm summer has caused green-blue algae to spread rapidly along the Swedish sea shores, and children and animals are advised to stay out of water, the Swedish Television SVT reported on Thursday.

The poisonous algae causes nausea, fever, vomiting and rashes if it gets in contact with skin. The situation is worst in Southern Sweden.

"We advise people not to swim in turbid waters or anywhere where you can see algae bloom or something that is believed to be algae bloom," microbiologist Caroline Schonning from Public Health Agency of Sweden told SVT.

The poisonous algae emit toxins that can harm people and especially children who are more sensitive than adults. Animals are also sensitive to the poisons and there are even reports of dogs that have died.

The extremely warm summer has caused sea waters to warm up to 23 to 25 degrees Celsius. According to SVT, this is the perfect temperature for the green-bleu algae to thrive. The problem is further reinforced by weak winds as the sea water stands still.

The situation is expected to culminate during the weekend and ease up during next week when colder air and winds arrive.