According to experts, Mr White's experience is typical of the handful of adder bites reported each year in Britain. "A few people get bitten every summer, but it's quite difficult - you have virtually to stand on one before it will attack," says Mark Nicholson, Cornwall Wildlife Trust's education officer, and a reptile specialist. "It's not a pleasant experience and you should certainly seek medical attention, but only 12 people have died from adders during the last 100 years - and the last fatality was in 1975. You have far more chance of being killed by a wasp."
Adders - Britain's only venomous snake - have much more to fear from humans than vice versa. "A few are killed by buzzards and hedgehogs," explains Dr Fred Slater, a herpetologist from the University of Wales. "But man is much their worst enemy."
Jim Foster works for Frogline, a Suffolk-based charity dedicated to protecting amphibians and reptiles. "We had one particularly unpleasant incident about a week ago when a pair of adders were killed and draped over a fence on a Norfolk nature reserve," he says. He adds that although such senseless acts go some way in explaining a decline in numbers over the past 30 years, the main problem is habitat destruction.
The reptiles depend on plenty of ground cover to hunt and have suffered badly from the loss of hedgerows, heathland and rough grassland. As a result, although they can be found throughout mainland Britain, they are patchily distributed. On the other hand, where they do occur they can be quite common - particularly in spring when they emerge from hibernation. To confuse matters further, most sightings are cases of mistaken identity: in a recent Scottish survey, 95 per cent of reports turned out to be slow worms - legless lizards.
In fact identification should be straightforward. Although colours vary considerably, adders usually have a diamond pattern running along their spine and rarely exceed two feet. Equally revealing is their habitat which is typically chalky or sandy heathland and bog edges.
This comparative rarity is a pity. Although relatively harmless to man, the snakes are efficient pest controllers, living mainly on small rodents. Their life cycle is a source of fascination, too. After surviving the winter lying dormant beneath ground, adders often spend their waking weeks communally, mating and warming up by basking in the morning sun.
By early June these gatherings disperse and for reasons which are not properly understood, for the next five months the pregnant females fast, before giving birth to between one and two dozen young. The family then breaks up, and from then on it is a rush to eat as much as possible before the winter hibernation. Prey is caught with a venomous bite and the snake then follows its victim's scent trail, tackling it after the poison has taken effect. Because the venom is so mild, however, even a mouse can travel a considerable distance before collapsing.
For anyone unfortunate enough to be bitten, this is worth bearing in mind. "My bite was nothing," says Mr White. "In fact the doctors were the worst part - when I phoned two hospitals for advice, I was brushed off and told not to be hysterical. Until then I was totally calm - it was their disbelief that hurt most."
For more information on adders and where to see them, Froglife has a free leaflet. Send a sae to: Froglife, Triton House, Bramfield, Halesworth, Suffolk IP19 9AE
What to do if you are bitten by an adder
Don't panic or run for help. The venom causes cell damage, and increased circulation only leads to greater problems. Usually the venom takes a while to take effect. Localised pain and swelling are common, so is blistering around the wound. The toxin is also a powerful muscle-relaxant, so it can lead to a loss of control in limbs and body functions, and respiratory trouble.
Consult a doctor as soon as possible. Treatment usually consists of antihistamines to reduce the swelling and anti-biotics for possible secondary infections. An anti-venom is available, but rarely prescribed because side-effects can include extreme allergic reactions
The toxin continues to damage tissue for four or five days, so try to rest the bite area as much as possible.