When you think of firefighters, you don't tend to think of lanky, weak blondes. You think rippling muscle, sweat droplets on tanned, firm skin and that uniform.

Or at least, that's what I had always thought.

A couple of weeks ago I spent two days training as a firefighter with South Wales Fire and Rescue, and it was very, very hard. I have never been so hot, exhausted or sweaty as I was those two days. I had never truly appreciated exactly what firefighters do. To be honest, I had never really considered it, apart from thinking it had something to do with fire, poles and kamikaze cats stuck up trees.

But after half an hour in the company of Roy Margetts, a retired firefighter with almost 30 years experience, who now makes his living instructing fresh-faced young recruits like myself, I soon changed my mind.

Day One saw me arrive at the Cardiff Gate training centre to get kitted up and go through some of the tests young bucks eager to enter the world of firefighting go through.

After a brief tour I was given fire boots, firefighting leggings, fire tunic, firefighting gloves, flash hood and a fire helmet Then it was time for the dreaded fitness tests, in full kit.

We started with a ladder lift, a test of upper and lower body strength, and Roy showed me the correct hand over hand technique needed to lift and lower the weight by pulling on a rope.

"All set?" He asked me with a vaguely sadistic glint in his eye.

"Pfft, obviously!" I replied confidently as I grabbed hold of the rope and started pulling. And pulling. But nothing happened - I couldn't even lift it an inch.

After watching me frantically tug, dangle and hang off the rope for a while, Roy kindly took off some of the 50 kg weight, but it was still almost impossible, and I certainly didn't manage it in the allocated time.

I then did an equipment carry, which is a test of aerobic fitness, muscular strength and stamina. I had to drag a hose reel from an appliance for 25 metres, jog back 25 metres, pick up and carry two coiled 70 mm hoses for 100 metres, carry one coiled 70 mm hose at chest height for 25 metres, jog back 75 metres, pick up and carry a 30 kg simulated light portable pump for 100 metres, and drag an eight stone mannequin around a course.

After a lot of huffing, puffing, swearing and outright refusal on my part to go through any more, we had a quick tea break before heading back out again.

We drove in one of the standard fire engines. or 'appliances' as those in the biz call them, and headed down to the grave of abandoned cars, where trainees are taught how to use hydraulic cutting equipment to free trapped people following road traffic accidents.

The equipment was basically normal tools made huge and hydraulic - like giant pliers for cutting through metal with the ease of a hot knife through butter. I was allowed to smash a passenger door window and cut through the metal of the support, which was very cool.

Day Two saw me arrive at Malpas Fire station bright and early where I was met by station commander Dean Loader.

The station is home to specialist equipment including full-sized mannequin horses, to practise horse rescues, and bariactric equipment.

While we were heading upstairs for a cup of tea, the special rescue unit, who do everything from rope rescues to RTCs had a call out. ~The team were in an engine and gone before I could register what had happened.

We then headed to Duffryn station for a three-way joint exercise with Maindee. A life sized (and weighted) mannequin was put at the end of a sewer, and the firefighters were expected to rescue it in full gear including breathing apparatus.

Luckily, I wasn't expected to do all that - but I did have to squeeze myself into a dry suit, which was a bit like trying to force an elephant into a tutu. I then had climb through a manhole, down into a suprisingly fresh dark hole.

It turned out the 'sewer' was actually a storm drain with excess water from Newport's reens rushing through it, but I was warned there were still rats and eels down there.

I jumped into the water so I was out of the way and could see we were in a small, man made cave, with three smaller 4.5ft high dark tunnels coming off it. One of the tunnels would be tackled by the firefighters. The second came from an outside reen, but the third was absolutely terrifying, pitch black with a net of spider webs across the entrance.

I watched the firefighters weighted down with breathing apparatus crouch down and disappear into the dark tunnel at 10-minute intervals and felt glad I wasn't expected to do that as well.

After that it was back to Cardiff Gate for a quick lunch where I met Roy and Huw Jakeway,Chief Fire Officer for the South Wales Fire and Rescue, for a quick chat.

Then it was time for my abseil.

I was harnessed, roped, and given a quick briefing and before I knew it I was trying to climb over the side of a massive metal tower in my full fire kit, which restricted me and made me even clumsier than normal.

Once I had let go of the side I had a whale of a time and didn't want to reach the ground.

Then it was time to put on my breathing apparatus and fight a fire. It was tight and sealed around my face and I had a brief moment of intense panic when I couldn't get any oxygen - the pump was stuck, but after a big pull on it, it started working and I sounded like Darth Vader.

The training centre has a purpose built house which can be filled with a controlled gas fire.

In my heavy kit and breathing apparatus it was difficult to move or indeed hear, and Roy, who was similarly attired, had to gesticulate for to me to follow him. We walked into the hallway and up the stairs, with the heat growing more intense until we were outside the room which was on fire. We walked in and the fire blasted up the opposite wall and raced across the ceiling towards us. The heat was searing, like nothing I'd ever experienced, and it deadened out even the sound of my own noisy breathing kit.

We knelt on the floor and Roy showed me the best way to tackle fire with a hose - short, sharps bursts which create a spray of water droplets are better at putting the fire out than wildly spraying, which can cause blistering steam.

It was completely surreal - the massive bursts of flame, the darkness, the heat - facing fire at that proximity and temperature brings back all these primal instincts to run, and it was strange having to repress that very basic need to flee.

I can't see how firefighters in a real situation can bear it - it clearly takes some serious courage.

When we went back into the cooler corridor I felt strange - while faced with the fire my body had been constantly sweating to negate the heat, but when we went outside my suit felt like it was filled with hot steam.

The house was then filled with artificial smoke.

The fire was out but the heat was still intense. We climbed back up the stairs and were confronted with the blackest darkness I've ever experienced.

I couldn't see my hand in front of my face and I couldn't see Roy or the other instructors. All I could do was feel Roy's shoulder as I followed him around the room and keep my other hand on the wall to my right.

Suddenly we let go of the wall and I followed Roy into the middle of the room where he suddenly ducked away, leaving me by myself.

The stifling dark, the smoke and the heat combined with my heavy, hot kit, my tight face bask and the loud sound of my own breathing through the BA kit along with the panic of finding myself alone was one of the strangest and most horrible experiences of my life.

I froze in the pitch black for what seemed like hours, but was probably only seconds, before slowly, slowly, shuffling forward until to my relief, I touched the wall.

Before we went in Roy had told me in those circumstances to find a wall and follow it as it will always eventually lead to a door.

I swallowed my escalating panic and the conflicting feeling that I was both claustrophobic and in the biggest room in the world, and slowly walked while keeping one hand on the wall until I found a doorway.

Roy soon found me and showed me the instructors had been watching me with a special camera which could see through the dark and the smoke.

After we left the house I was exhausted, sooty, sweaty and stank of smoke.

The whole experience was very intense, but I had loved it, even the scary bits. I have so much respect for firefighters.