Good morning. Record-breaking heat is dominating life for millions of Canadians – more on that below, along with the limited damage to Iran’s nuclear program and BlackBerry’s rebirth. But first:

• Trump says Iran’s nuclear program is obliterated and the ceasefire with Israel going well
• Carney is ready to dismiss top bureaucrats who are unable to meet his high expectations, Liberal insiders say
• CBSA investigates whether suspected senior Iranian officials were allowed entry into Canada

In a good chunk of Ontario and Quebec right now, it’s the kind of hot that makes it hard to think much about anything beyond the heat. Sure, I watched Donald Trump drop an f-bomb over the shaky ceasefire between Israel and Iran. I tried to crunch the numbers on how Canada will find $150-billion to spend each year on defence. I wondered if Jeff Bezos would change his Venice wedding plans once protestors threatened to clog the canals with inflatable crocodiles. (He did.) Then I went back to scrolling for A/C units with my profoundly sweaty fingers.

Millions of Canadians are currently living underneath a heat dome, where high pressure clamps a lid on sweltering air and turns cities into steam rooms. Toronto, Montreal and Ottawa just broke weather records – temperatures are 10 C warmer than normal for this time in June. But as any dad will tell you, it’s not the heat, it’s the humidity. All that extra water vapour in the air means it feels like the low 40s outside.

That’s because it’s impossible to cool ourselves down when the weather is so soupy. We sweat a bunch once we get too hot, and the evaporation of that sweat carries away heat to lower our internal temperature. We’re good at this: We have between two and four million primary sweat glands, 10 times as many as our clammy chimpanzee cousins. But when the air around us is already saturated with moisture, there’s nowhere for the perspiration to go. We become our own personal heat domes, sweating even more and getting even hotter.

Has climate change made humidity worse? I think you know the answer to that. For every 1 C rise in average temperature, the amount of water vapour the atmosphere can hold goes up by about 7 per cent. A 2025 study of U.S. climate regions found that humid heat waves have increased in severity over the past four decades, especially across the eastern states. If global temperatures increase by 4 C – which the UN fears could happen in the next 50 years – humid heat waves that feel like 55 C may become biennial events in the U.S.

Of course, southern Canada is already warming at roughly twice the global rate, and it’s faster still in the North. That’s a result of Arctic amplification: When you don’t have as much snow cover in the winter, you’re exposing darker ground, which absorbs more heat (and melts more snow, creating a feedback loop). For similar reasons, urban areas are warmer than rural ones: All that concrete and asphalt traps heat during the day, then releases it slowly at night. Until 1990 in Toronto, for example, the city averaged fewer than 10 days each year where daily temperatures topped 30 C. By 2020, that average had reached 14 days. At this rate of emissions, Toronto could have 55 days of temperatures in the 30s by 2050 – and that’s without factoring in the humidex.

So it’s not great that, earlier this month, Canada’s environmental commissioner said our late-to-the-game climate change adaptation strategy is already falling short. It’s not great that, just to the south, the current U.S. administration has taken a flamethrower to basically every environmental protection act. There is a bit of good news for my fellow dome sufferers: The heat and humidity will break later today. But much like Trump’s efforts at diplomacy, it’s a fleeting reprieve. More 30 C days are on deck for southwestern Ontario later this week.

Israeli forces opened fire on hundreds of Palestinians seeking food in Gaza yesterday, killing dozens and bringing the death toll outside aid sites to more than 500 in the past two weeks. Although 15 human rights organizations warned that the U.S.-backed Gaza Humanitarian Foundation could be complicit in war crimes, the White House just approved a US$30-million grant to the group.

Abroad: A new U.S. intelligence report found that Iran’s nuclear program has been set back only a few months after bunker-busters dropped on its sites last weekend.

At home: The union representing thousands of striking DHL employees alleges that the delivery giant is breaking federal law by using replacement workers.

Profit: BlackBerry