A nation's industrial development begins with junior engineers.

Upon arriving at an inconspicuous courtyard, two men in Zhongshan suits were already waiting at the gate.

After handing over the items, the soldiers at the door didn't take them directly. Instead, they opened the lid and carefully inspected them. The electric pressure cooker was fine, but the air fryer, with its large lid, seemed to want to unscrew it and look inside.

Fortunately, one of the middle-aged men spoke up to stop them.

Jiang Xia looked up and exclaimed, "Hey, isn't this Professor Zhang's son from yesterday?!"

I was originally going to give you some instructions on how to use the two pots, but this saved me the trouble.

As for going in to demonstrate it himself, Jiang Xia had considered it, but it turned out he was overthinking it. The man in the Zhongshan suit took the handwritten instruction manual from Jiang Xia, nodded slightly, and went inside without saying a word.

Hey, yesterday you called me your good uncle, but today you're acting like you don't know me.

Truly ruthless!

The matter is settled; now wait for further instructions!

Jiang Xia looked at Wang Kui, revealing eight teeth: "Brother Wang, do you still dare to go to the Ministry of Chemical Industry?"

Wang Kui's lips twitched: "There's no place in the world I wouldn't dare to go!"

……

At the intersection of Hepingli Road, in the alley next to it.

Jiang Xia was kicked off the jeep by Wang Kui.

"Brother Wang, it's still two subway stops away from the Ministry of Chemical Industry!"

"Young people should take a walk and get some exercise. The weather is perfect today, not too cold or too hot..."

"There's a path here, just go straight and you'll get to that lab! It's only a few steps!"

Jiang Xia looked at Wang Kui suspiciously, and Wang Kui turned his head away somewhat guiltily.

Twenty minutes later~

"Wang Kui! You bastard! We can't get through the alley!"

Wang Kui, inside the car, sneezed: "Tsk, the weather's really about to change..."

Two hours later, Jiangxia was still nowhere to be seen.

Wang Kui was getting anxious and was just thinking of going to look for him when Jiang Xia came bouncing back in a donkey cart.

Don't be curious why donkey carts can roam freely on the streets of Beijing.

These days, you could drive an oxcart right past Tiananmen Square and nobody would care.

With a stern face, Jiang Xia threw a large cloth bag into the back of the truck, and then carefully loaded some glass bottles and jars onto the truck.

Then, with an excited expression, he urged Wang Kui to go back quickly.

Back at the factory, Jiang Xia, carrying a pile of things, plunged headfirst into the confidential workshop.

There weren't many people in the small workshop at the moment; about a dozen of the two pots had been assembled and were sitting there.

"Brother Wang, could you get me some white vinegar?"

"Brother Wang, could you get me some sawdust?"

"Brother Wang, go get some iron filings from the floor of Workshop Two!"

"Brother Wang!!!"

"Brother Wang..."

Wang Kui was so busy he was dizzy and disoriented. In the end, he watched with a dark face as Jiang Xia put a bunch of things into the big beaker, stirred them, poured them all into the transparent PVC bag, and carefully sealed it.

Then I watched as Jiang Xia clamped the opening of the transparent bag with two steel plates, heated it under the heating element for a while, and finally put it into a coarse cloth bag.

Jiang Xia couldn't help but chuckle as she looked at Wang Kui's dark face.

Who told you to make me take the wrong path?

He tossed the cloth bag over, indicating to Wang Kui to gently rub it.

Then they got busy again, as preparing a supersaturated sodium acetate solution was quite difficult.

It needs to be heated over a low flame and stirred constantly; it will be troublesome if it boils.

Fortunately, the chemical equipment we brought back was quite complete, including two alcohol lamps.

Jiang Xia, using both hands simultaneously, looked like a shaman performing a ritual.

"It's hot! It's so hot!"

Wang Kui rubbed the cloth bag that Jiang Xia handed him for a while. At first, he didn't pay attention to it and thought that Jiang Xia was just being petty and making a fuss.

Unexpectedly, the more I rubbed it, the warmer the cloth bag became.

Finally, it even started to get slightly hot to the touch.

"Hehe, how about that? Didn't come for nothing, right? That's what you call science!"

Seeing Wang Kui's surprised expression, Jiang Xia grinned.

"There's something even more amazing coming up! But you'll have to help me stir things up first, my hand's cramping up!"

Jiang Xia wore a bitter face, not a smile.

Wang Kui was wearing only a single layer of clothing today and felt a bit cold, so he casually put the small cloth bag into his chest pocket.

Jiang Xia quickly took it out for him, added some padding, and then put it back in.

Just kidding, at 50 degrees Celsius, if you keep it right next to the meat, you could probably cook that piece of meat on the chest until it's half-cooked.

As the temperature gradually rose, Wang Kui felt warm all over. He took the glass rod from Jiang Xia and continued stirring.

By the time Jiang Xia called a halt, Wang Kui's hands were sore.

A sour smell permeated the small workshop.

Wang Kui then took out the small cloth bag, looked at the slightly reddened skin on his chest, and asked thoughtfully, "How long can this little thing keep warm?"

"I don't know, but theoretically, a mixture of 50 grams of iron powder should be able to generate heat for more than 20 hours. The average temperature is quite high, probably around 5 or 60 degrees Celsius!"

"But this is a one-time use."

"This can be reused!"

Jiang Xia gestured to the solution he had just prepared.

"Hiss~ What's wrong with your brain! But this thing can generate heat once it's made, right? What's it for?"

"Trying to use you as a hot water bottle, you blockhead!"

"My master's wife's foot injury aches in cold weather, and my master also suffers from rheumatism. Putting this in the blankets will surely make things a lot more comfortable!"

Wang Kui listened and nodded. He also had an injury, on his chest.

When it gets cold, it gets itchy and numb, but this cloth bag really made me feel much better.

"As for this, you can put it directly against the skin with a layer of cloth between the layers." Jiang Xia gestured to the solution he had just prepared. The reaction temperature was low, only about 3 or 40 degrees Celsius.

Iron powder, white vinegar, and a little sawdust can generate heat for so long?

Wang Kui's eyes lit up, and he grabbed Jiang Xia, urging him to make a few more, saying things like the brothers hadn't received their winter clothes yet and it was really uncomfortable to stand guard in just a single layer of clothing.

Jiang Xia suddenly realized why the soldiers at the door were trembling slightly, even though they were standing ramrod straight when he entered.

If it's like this during the day, it must be even worse at night.

Anyway, this disposable heating pack is simple; iron powder and sawdust are plentiful in steel mills. The white vinegar is thanks to Li Huaide's recent gluttony.

Three large vats of white vinegar were sitting there, leaving Director Sun unsure of what to do with them.

On the contrary, the plastic bags that are common in later generations are hard to find.

However, this time Jiang Xia also managed to get a small pile from the Ministry of Chemical Industry's laboratory by using his facial recognition.

If you want more, then you'll have to find something to exchange for it; Jiang Xia isn't that shameless.

After a flurry of activity, more than forty heating packs made of iron powder and more than twenty of those made of supersaturated sodium acetate were produced.

It's not that we can't get more; Jiangxia got a huge bag of sodium acetate from the Ministry of Chemical Industry.

The PVC bags are no longer available.

Wang Kui looked at the remaining raw materials with some regret, considering that the security department had over a hundred people in total.

There are more than 30 people on night patrol, so if you calculate it like that, they'll all be used up in one night?

As for the supersaturated sodium acetate version with low calorific value, Wang Kui didn't take it seriously.

"Hey, Brother Wang. Want to go to the Ministry of Chemical Industry again? It seems Director Liu from the Equipment Department hasn't returned yet!"

Wang Kui glanced at Liu Hongjun and the others, who were holding heating bags and looking blissful, gritted his teeth, and turned to leave.

Wang Kui walked briskly ahead, with Jiang Xia following closely behind.

Jiang Xia felt very pleased with herself when she thought about how Wang Kui had also been ripped off by the bigwigs in the Ministry of Chemical Industry.

Huh? Why didn't Wang Kui leave the factory gate? Why did he go straight to the factory office building?

Hey, how did he get into Li Huaide's office?

Hey, why are you smiling when you come out?

"Wait, don't come home until you've finished packing that pile of materials!" Wang Kui flicked Jiang Xia's ahoge with his finger and said casually.