Hot weather makes ideal conditions for a stroll by the river – unfortunately it also makes optimal growing conditions for a weed which causes severe blistering and blindness.
Giant hogweed, an invasive species, which grows beside rivers and footpaths is on the increase.
And contact with sap from the plant can cause severe blistering and even temporary blindness.
The plant looks like common cow parsley but it is much bigger reaching five metres tall with umbrella-shaped clusters of flowers growing up to 80cm across.
Giant hogweed was imported to Britain by Russian botanists but managed to spread from gardens to the wild.
NHS Choices recommends the following should you come into contact with the plant: “If you touch a giant hogweed, cover the affected area and wash it with soap and water.
“The blisters heal very slowly and can develop into phytophotodermatitis, a type of skin rash which flares up in sunlight. If you feel unwell after contact with giant hogweed, speak to your doctor.”