Fifty feet underground, in one of the most secure rooms in Israel, is the country's blood vault.
We're told we can't say its exact location and they won't reveal what measures have been taken to protect it, but it is safe against missile, chemical, and cyber attacks, and in the air-conditioned room are boxes and boxes of blood of every type, hundreds of litres ready to be used in mass casualty scenarios.
War between Israel and Hezbollah is looming and so plans are being readied for another conflict.
Not far away, in part of the same subterranean complex, is a new operations room for Israel's national ambulance service, Magen David Adom (MDA).
On the outbreak of war between the two sides, this would become the hub for all emergency calls.
MDA chief of staff Uri Shacham tells us it is "completely secure, completely connected and it allows us to keep answering calls even under missile attack".
The worst-case scenario is a complete communications blackout. Hezbollah has the capabilities to do that, and so the emergency services are working on a plan for that eventuality - a relay system using human messengers.
Mr Shacham said: "From the IDF I would know that a missile probably hit in this or that community, so we will send motorcycles to provide first aid, collect information, and bring it back to the central dispatch."
Air raid sirens
As we are filming, air raid sirens sound on the northern border and also inside the control room.
The systems can predict where the missiles might land and an ambulance is dispatched before a call comes in so no time is wasted.
They reckon they can now attend any emergency call in Israel within five minutes.
A huge number of donations following the 7 October attacks have allowed it to buy dozens of small community medic vehicles which have been allocated to villages and towns most at risk.
They have also stockpiled essential medical supplies to last three weeks if international aid can't be flown into the country.
Please use Chrome browser for a more accessible video player
2:01
When, not if, Israel will go to war
Ask people in Israel now, and most people will tell you it's a matter of when, not if, they go to war with Hezbollah.
Israel's leaders have said they will invade if diplomacy doesn't work, and so far the talking has achieved little.
The war in Gaza is still being fought, but the country is bracing for the next conflict, with a far more formidable enemy and an uncertain outcome.
A fortified hospital deep in a car park
Haifa is barely 28 miles (45km) from the Lebanese border and within sight.
The city's main hospital would become the centre for all the wounded and has already readied its fortified hospital.
Level minus three of the hospital's underground car park has been converted into a five-acre hospital with 1,200 beds and facilities.
The car park was built after the 2006 war with Lebanon and designed with the next conflict in mind.
The parking bays have racks of electricity points and oxygen taps pre-installed.
Eyewitness:
Risk of war rising in Lebanon
Destruction in Lebanon's 'ghost towns'
Violence won't stop until Gaza war ends - Hezbollah chief
Innovation born from experience of war
Plumbing was built into the columns so that toilets and showers could be quickly fitted.
Even the flooring around these areas was made non-slip. A secure control room has video feeds around the hospital and city and encrypted communications to liaise with the military and government.
Thousands more beds can be set aside on the floor above for the children and partners of staff and patients.
Little has been left to chance. It's innovation born from the experience of war and the certainty of another.
Follow Sky News on WhatsApp
Keep up with all the latest news from the UK and around the world by following Sky News
'We are really scared'
Around 80,000 Israelis have been evacuated from border villages because they are being hit by missiles and anti-tank fire every day.
Israeli Prime Minister Benjamin Netanyahu is under pressure from many Israelis to launch a ground invasion to push Hezbollah back once and for all so people can return home. A similar number of Lebanese have left their homes on the other side of the border.
But in downtown Haifa, which is a mixed city where Jews and Muslims live alongside each other, we didn't meet anyone who wanted a war.
Datawrapper This content is provided by Datawrapper, which may be using cookies and other technologies. To show you this content, we need your permission to use cookies. You can use the buttons below to amend your preferences to enable Datawrapper cookies or to allow those cookies just once. You can change your settings at any time via the Privacy Options. Unfortunately we have been unable to verify if you have consented to Datawrapper cookies. To view this content you can use the button below to allow Datawrapper cookies for this session only.
Enable Cookies Allow Cookies Once
"We are really scared of course," Saleh Al Saadi, a Palestinian factory worker, told us.
"I worry about the children mainly and the soldiers have been fighting for too long. It's affecting our lives."
Ron, an Israeli also from Haifa, agreed.
"When Haifa will be destroyed, and Beirut will be destroyed and Israel will be destroyed and Lebanon will be destroyed, the only people who are going to suffer are the people."
Hezbollah bigger and more heavily armed than Hamas
Other Haifa residents we spoke to, said they are already planning their escape if war breaks out.
Read more:
Newborns in Gaza 'have little chance'
Prospects for West Bank are bleak
Hezbollah is a much bigger, better-armed, and more battle-hardened force than Hamas.
Hezbollah says it doesn't want a war and will call a ceasefire immediately after there is a truce in Gaza.
Israel says fighting with Hezbollah could continue, even with a Gaza ceasefire and it might be forced to invade to bring security to its border.
But war between the two sides would be deadly for both and could drag in the whole region.
