I’m lying naked, in a sauna by a tranquil lake in the Latvian countryside, head-to-head with my cousin, El, while a man wearing only a pointy green hat and a clinging skirt shakes water from birch branches over us. If there’s ever a moment when you realise just how much of this industry is based on blind trust in total strangers, this is it.

"This isn’t what I had in mind when you said we’d be visiting a spa," says El. By the end of the three-hour session, she changes her tune – even claiming it’s awakened a new spiritual sense in her. But for now, we’re sweating away in a 65°C pirts – the Latvian word for sauna – and Aigars, our sauna master, is whisking the wet leaves over my body, first tapping, then whipping the branches against my skin.

"Some people like you to hit them hard," explains Aigars, "but I like to use steam and massage techniques to get the effect." It’s much more pleasant than it sounds, all this hitting business – it’s gentle enough that it can be done over sensitive areas – although it’s still not exactly nice in the moment.

The pirts is so hot it’s hard to breathe, and the air feels like it might contain actual flames. The hats we wear have a hole in the top and are made to protect the head from the intense heat. The only relief is from the dripping branches, or when Aigars lets in a blast of crisp air – which he does in response to my skin turning too pink. He’s trained to read the body, he says, to know how people are feeling.

I’m feeling unbearably hot as I rest on a pile of damp birch branches, and then whoosh – Aigars dumps ice-cold water over both me and El. I shriek, but after the initial shock, it’s actually blissful relief. For a few moments, that is, before Aigars gets back to whipping the branches through the air, making it even hotter than before.

"Had enough?" he asks after some time. "Yes," we both agree. We sit up slowly to avoid dizziness, don comfy robes and head outside for some fresh Baltic air.

Welcome break
It’s incredibly peaceful outside and my ears buzz – from the quiet or the heat, I’m not sure which. A deck looks out over a still lake flanked by trees and the only sound is of an occasional goose passing overhead.

We’re about an hour outside Latvia’s capital city, Riga, deep in the grounds of Rumene Manor, a lovingly restored, 10-bedroom neo-Gothic hotel. The pirts is in a traditional, lakeside pine cabin, first built in 1935 and reconstructed in 2014.

We rest, slowly cooling on chairs until Aigars calls us back into the cabin’s lounge with a blazing fire. He’s made us yarrow and cowslip tea, served in traditional thick, black earthy mugs crafted locally.

He’s also laid out delightful bits of food: local cheeses, truffled salamis, fresh figs, raspberries, pine nuts, dried tomatoes. Suddenly I’m famished. "It’s important to eat while you do the pirts," he says. "You should feel energetic when you’re done and you need to keep your nutrition levels up."

Aigars warns us not to spend too much time out of the sauna – just a break to let the surface of the skin cool and allow the heat to travel further into the body.

Grounding experience
The next two sessions, also split by a short break, are similar to the first but progress in intensity. At one point, my head cocooned under a pile of cool, wet birch leaves, I have an amazing sense of my body as a separate entity as Aigars presses hot leaves into the small of my back. The sound of my breath against the leaves and the sizzling water on the sauna rocks lulls me into a heightened sense of relaxation.

At the end, Aigars wraps me in a linen towel, walks me to the lake and instructs me to wade into the water. Mud oozes between my toes and the icy water pricks my skin. I hesitate."Àtrāk! ātrāk!" he says, urgently. "Faster! faster!" and I obey. "Now under the water!" he says, and I duck below the surface before I can think. When I resurface, gasping with shock, Aigars guides me to a whirlpool on the deck.

The water in the tub is cold, but feels balmy after the icy lake. "Now I hold you on your back and you relax," Aigars commands. Water rushes into my ears and as I float, I can hear my blood pulse. My breath begins to slow and I feel like I’m spinning.

At the end of the experience, I open my eyes to grey clouds above and focus on the silhouette of a pine tree to ground myself. I’m not spinning, it turns out. The world is there, and quiet. The only sound is of my own breath and the cool water lapping gently at my skin. I’m invigorated – buzzing with a new energy – and fully present in the moment.