They must surely be Scotland's most adventurous schoolgirls - dodging deadly snakes and scorpions as they cross the African desert in blistering heat.
Tracking endangered elephants and investigating prehistoric cave paintings in the mountains, they encounter rare black rhinos, giraffes, zebras, baboons and jackals during their trek across Namibia.
They have experienced more excitement than many of us will have in a lifetime and their five-week African adventure across a wilderness of desert and into the mountains has whetted their appetite for more.
Now back at Dunblane High, 17-year-old Johanna Martin is visiting other Scottish schools, urging them to follow their lead on the journey of a lifetime with the British Exploring Society.
The hours of babysitting and cake-baking eventually paid off for Johanna and Beth Cochrane, when they funded their scientific expedition across Namibia last summer. They're now passing the baton to fifth-years Sarah Huggett and Olivia Donnet, two 16-year-olds who are among the group to follow their footsteps across Namibia this summer.
Travelling with the British Exploring Society (formerly known as the British Schools Exploring Society) and visiting remote regions of the world has become a traditional rite of passage for this school's most intrepid teenage travellers, thanks to the commitment of geography teacher Shelagh Hansom, who is also principal teacher of pupil support.
"I have been involved with this now for about 15 years and on average I would say we have about four to five students each year who go," she says.
These expeditions to remote regions across the globe are described as "adventure with purpose" and combine science fieldwork with adventure and exploration. Students from this school become Young Explorers each year, as a preparation for leaving school and heading off to college or university.
Mrs Hansom also has valuable insight as the mother of Young Explorers. "My husband was very involved with the British Exploring Society in terms of leading a lot of the expeditions and I have three children and they all went on expeditions," she says.
"I just think it's a once-in-a-lifetime opportunity. It's also a unique opportunity to travel and see a part of the world that they will probably never get to again, because British Exploring prides itself in wilderness locations that really are becoming more at risk."
In August 2011, British teenager Horatio Chapple was killed in a polar bear attack during one of the society's expeditions in northern Norway. The tragedy underlines the potential hazards for travellers in remote, harsh environments, but hasn't discouraged these Scottish teenagers from taking part. Johanna Martin has been out at Beaconhurst School in Bridge of Allan, spreading the word about this year's expeditions.
"I really feel everyone should at least hear about this and then they can choose whether they want to take up such a great opportunity," says the sixth-year pupil.
The experience has made a profound impression on the two girls - "I think because I got to try new things and I got to meet new people," Johanna explains.
She's using the expedition for her Duke of Edinburgh's Award. "It's just a really good experience," she says, "because beforehand you have the challenge of raising the money and then once you're out there you have to try new things. You have to get into everything - you can't just sit back or you won't learn new things."
One focus of the fieldwork in Namibia was to track migratory elephants and another objective was to locate, map and catalogue prehistoric rock art for the Trust of African Rock Art. These cave drawings and carvings were made by the San Bushmen in the Brandberg mountain caves more than 3,000 years ago.
Cataloguing the cave art was a highlight for Johanna, who also did a project on insects during her trip. "The rock art was absolutely gorgeous," she says.
"Most of it is red because sometimes they would have mixed their blood into it. These are drawn up where they would have been sleeping and living, and so this was a really spiritual place because they would be marking their territory," she explains, with the help of some of the photographs she has taken.
On a trek out to the wetlands, she had the privilege of another extraordinary experience, which she outlined in her journal: "My leadership skills were then also tested during a face-to-face encounter with a circling black rhinoceros bull. The group had to be safe, so leading them to any high ground, as he already had that advantage, was a must; though the discovery of another black rhinoceros and her two calves on the opposite horizon put us in a spectacular position. Considering this is one of the most endangered species of the world, I realise just how lucky we were to see them."
Each expedition splits into several groups of 12 or "Fires", as the society's founder, surgeon George Murray Levick, named them - the number of people who could be seated comfortably around a campfire. He was one of the Northern Party in Captain Scott's last Antarctic expedition and set up the former British Schools Exploring Society in 1932.
One group on a trainee leaders programme with the girls' Namibia expedition had the good fortune to come across a herd of 38 desert elephants. But even without a personal sighting, Johanna's friend Beth Cochrane, in another "Fire", was thrilled with the work collecting data on the elephants.
"It was really exciting getting to know the elephants," Beth says. "Getting to understand where they were walking, how fast they were walking, how many of them were there, the destruction they caused.
"They're big animals - if there's something in front of them they're not going to go round it, they'll go over it if they can. It was really interesting getting to know them, even if you didn't see them."
She explains why she chose Namibia over other destinations, with a Scottish teenager's typical candour and humour: "I got the option of the Arctic, the Amazon and Namibia. I don't do well with humidity, it makes my hair really frizzy. And the Arctic? I live in Scotland, so it's pretty cold anyway.
"And I have fallen in love with Africa, ever since the first time I went. My dad lived in Zambia for quite a few years, so I guess the love of Africa came from there and getting the opportunity to go - I just couldn't turn it down," she says.
But this isn't a journey for girls or boys who can't live without hairdryers. They sleep in tents in the desert with buckets for loos and take turns on listening watch through the night, while others sleep. Then they rise at 4am to trek as far as they can before the sun is at its hottest.
Beth's group found lion tracks less than half a mile away from where they'd been peacefully snoring. "The lion prints were about 2km outside our camp one night. They were male lions and it's the female ones you've got to worry about," Beth says.
"The main danger was probably standing on a scorpion, because when you're in base camp - well, I didn't wear shoes - you wear flip flops or something. And the scorpions are really hard to see; even although they're black, they're hard to see and so easy to stand on," she says.
Four doctors travel with the expedition, which is also accompanied by local guides and expert leaders. But students learn how to fend for themselves in the desert, how to set up camp and find food, how to communicate and navigate and how to identify snakes and other reptiles.
Both girls feel their experiences have changed them. Beth says she would be more prepared to have a go at something now and feels greater concern for the environment. Johanna is aware her communication skills have improved. "I am much more confident - I wouldn't have sat here and talked like this before."
`THIS IS GOING TO SOUND CHEESY, BUT IT WILL HELP YOU TO DISCOVER WHO YOU ARE'
The marathon of making cupcakes and entertaining toddlers is well under way for Olivia Donnet and Sarah Huggett.
The 16-year-olds are already approaching their fundraising target for their African adventure, which includes a 100km trek through the Namib Desert to the Skeleton Coast of Namibia.
"When I was younger I used to watch the CBBC series Explorers and I just always wanted to go on one of these adventures, so I have been saving up since then," says Sarah from Dunblane High.
"With this, as well, you're not just getting survival skills, you are getting independence, leadership, organisational skills and seeing how you cope in stressful situations as well," says the fifth-year student who is considering a career in midwifery.
Like everyone who takes part, the girls have to use their initiative to raise money for their travels.
"It costs pound;4,500. I work at a cattery at the weekend, cleaning out the cats' cages and feeding them. And I babysit quite a lot for my next-door neighbours. I also have fundraising boxes I give to friends, family and neighbours, so they can put loose change in them."
Her friend Olivia has a passion for wildlife and an open mind about future careers.
"This is going to sound so cheesy, but I think it will help you to discover who you really are and maybe you will be able to discover things you might be able to do, that you maybe didn't think you could do before," she says.
"I've always been interested in wildlife, so that's one of the main things that attracted me. I did geography last year when we studied deserts - but it's mainly for the wildlife."
As well as Namibia, British Exploring Society expeditions for 16- to 20- year-olds in 2013 include journeys to northern Norway in the Arctic Circle and to the Indian Himalayas. There's a gap year expedition for 18- to 25- year-olds visiting the world's largest sand desert, the Empty Quarter of Oman. And a new university students' programme launched next year will visit the Indian Himalayas.