I've been wearing these gloves in open-water conditions from 5 degrees Celsius, and I simply don't feel the cold. I opted for the M as the S were sold out, and I'm relieved I have the M as they are rather short on the fingers. They are also tight to pull on and off - there's very little give in the wrist area - but they don't restrict movement in water. Very little water gets in. Don't be tempted to size down though! I'm glad I didn't. I lent them to a friend who has Raynaud's and she loved them.