You know those beautiful crisp spring mornings when you long to be out tramping over hills or through woods, not stuck in a centrally-heated classroom? And those sweltering summer days when it seems a crime not to be in the sea, surfing or sailing or just splashing about?
Well, consider this: there are more than 400 teachers in the UK who earn their living from outdoor education. They are leading groups up mountains and through gorges, into caves and on to beaches, all year round. Whether the focus is on citizenship or geography, biology or chemistry, PE or even history, they are teaching in some of the most beautiful landscapes in the country and watching children have experiences they will remember for years, perhaps for the rest of their lives.
Of course that means they are out in the wet and cold as well, when the rest of us might prefer to be huddled over a radiator. But that doesn't seem to bother these intrepid types. What they have in common is a personal passion for sporty outdoor activities, and a professional passion for what these activities do for young people.
Andy Hall, a one-time teacher of social sciences and geography who is now head of Arthog Outdoor Education Centre in south Snowdonia, says: "It is brilliant seeing eighty 10 and 11-year-olds coming in, soaked from head to foot after a walk along a gorge, and so massively enthusiastic and absoutely full of it.
"I love my climbing, my canoeing, my surfing, my kayaking. It's great to be able to share my enthusiasms and think perhaps the children will be inspired to do these things and get satisfaction from them in the future.
They go home with some understanding too about how important it is to look after the outdoors: to keep the water clean, not drop litter and conserve resources."
In the week about 80 per cent of courses at Arthog are for 10 to 13-year-olds. At weekends there are activities for adults too: perhaps funeral directors going climbing and caving and trying problem-solving challenges, or art teachers studying outdoor sculpture.
The pay is not great. Most of the teachers at centres such as Arthog earn only about pound;20,000, significantly less than they would be paid in the classroom - a sign perhaps of how much they value what they do. At adventure camps abroad where food and tent are thrown in, teachers in charge of groups of children earn only about pound;70 a week though managers make more.
For Ian Healey, head of Dean Field Studies Centre in the Forest of Dean, Gloucestershire, it is the change he sees in children over the space of a few days that makes his job so rewarding.
"Children build their confidence and self-reliance as they overcome their fears," he says.
"You can have a big tough rugby - playing lad or the school bully who is quaking in his boots at the thought of abseiling down a cliff while a little seven-stone girl is happily going over the edge with no problems.
The achievement and the sense of self-confidence they get from doing it are fantastic. They whizz back up to have another go.
"Caving worries them too because it is beyond their experience, it is going into the unknown. Yet when they actually do it, they find they really enjoy it..
"We say to them 'If you can overcome this challenge, think of all the other things you can cope with in everyday life.'
"I have known some children go on to train as instructors. Outdoor education had such an impact on their lives they decided to make it their career."
There are about 100 local authority funded centres in this country and a few run by private companies or charities. Then there are firms such as PGL which organise adventure holidays here and abroad.
For Ali Beynon, the experience of helping out a fellow teacher by escorting a school group on a trip to the Alps changed her life.
"I did it and was hooked," she says. "Seeing the children come out of themselves and the totally different relationships between them and their teachers - you get so much out of it. I thought: I want more of this."
She gave up her job as a Year 1 teacher in spring 2001 and has spent the five summers since working for PGL, three of them managing one of their centres in the south of France.
Out of season she came back to the UK and worked as a supply teacher although now, having got the travel bug out of her system, she is looking for a full-time permanent post where she can put her ideas into practice.
"I have learned such a lot from watching people who have been teaching for years and I want to be able to apply it," she says.
"I genuinely believe there's a lot to be gained from teaching all sorts of subjects in an outdoor environment."
The fact that during her summers in the south of France, near Beziers, she always had her bikini on under her T-shirt and shorts so that she could go windsurfing or kayaking if the chance arose, was not exactly a disadvantage either.
Of course despite the fun, running activities is not taken lightly. There is constant stress on safety, training, and risk assessments.
Andy Hall of Arthog says: "You can't put your hand on your heart and say it isn't dangerous, because things do happen in the outdoors and children sometimes do unexpected things.
"But, if anything, because my staff are so experienced and well-qualified, and working with groups of ten rather than classes of 30, children have fewer accidents here than at school."
The other big shadow hanging over outdoor education is funding. Despite acclaim from Ofsted and a manifesto for outdoor learning due out in September which is expected to lavish praise on it, many centres are struggling to stay open.
Ian Healey at Dean Field says: "We are on reduced funding so we have had to put up our costs and schools are phoning us to say they can't afford to come.
"That means we are losing any aspect of social inclusion. Inner-city kids who might benefit from it more than anybody are being financially squeezed out. It is very frustrating.
"We know what we do has a good knock-on effect back in the classroom, but it isn't measurable."