You wouldn’t dream of driving whilst texting or holding a mobile phone would you, but what about sneezing? No really, with a runny nose, itchy eyes and regular bouts of sneezing would a motorist be passed fit to drive? Well, hayfever affects amost a fifth of the population in Britain and as the season reaches its height hundreds of thousands of drivers will be affected.

The trouble is that those who attempt remedies may be placing themselves in even greater danger.

A few years back researchers at the University of Iowa found that Motorists using over-the-counter remedies to fight hayfever may be a greater risk for causing traffic collisions than drunken drivers.

They focused on medication containing diphenhydramine, which is used to treat allergies. "First-generation antihistamines such as diphenhydramine are known to affect driving performance," said Dr John M Weiler, professor of internal medicine at the university and lead author of the study. "However, we were surprised to find that this antihistamine has more impact on driving performance than alcohol does."