By Shawn Watts, CEO, Corfix
I used to think people were soft for taking water breaks. I didn’t believe in heat exhaustion, not really. I came up as an ironworker and the expectation was that you worked, you didn’t complain, and you definitely didn’t ask to sit in the shade because you were feeling off. Nobody said that out loud, but nobody had to, and everyone understood the unspoken rule.
The thing about heat illness that catches people off guard is that by the time someone looks sick, they’re already past the point where a cup of water fixes it. There’s no near-miss where everyone gets a scare and goes home fine. And the person most at risk is almost always the least likely to say anything, because the culture already told them not to.
Nobody on your site is going to ask for a break when everyone else is still working. You know this, because you wouldn’t have either.
The structural problem
Most heat safety programs rely on workers to self-report and self-monitor. Just drink water when you’re thirsty. Rest when you need to. Tell someone if you feel off. The trouble is that thirst shows up after you’re already a bit dehydrated, and “tell someone if you feel off” runs straight into a culture where admitting you feel off is the last thing most people want to do.
That’s why heat safety can’t be left to individual judgment in the moment. It has to be built into the structure of the day before anyone has to ask for it.
When water breaks are scheduled, nobody has to request one. When shade and rest are part of the plan rather than something you negotiate for, the dynamic shifts. The worker who’d never speak up gets the break anyway. The new apprentice who doesn’t know the site culture yet doesn’t have to guess whether asking is acceptable. The crew lead doesn’t have to choose between keeping pace and looking after people, because the plan already made that call.
Under Ontario’s Occupational Health and Safety Act, employers have a general duty to take every precaution reasonable in the circumstances to protect workers. There’s no fixed temperature trigger written into the legislation, which puts the judgment call on employers to build a program proactively, not reactively. A private member’s bill, the Heat Stress Act, 2024, would add specific heat protection requirements to the OHSA if it became law, but it’s been sitting at first reading since November 2024 with no further movement, so for now the general duty clause is what you’re actually working with.
IHSA and OHCOW both publish practical tools for this, including OHCOW’s Humidex-based Heat Response Plan, which gives a tiered way to scale your response to actual conditions on a given day instead of relying on a flat rule that doesn’t account for humidity.
Two frameworks worth understanding properly
Water, shade, and rest sound simple enough that people stop paying attention to the details, and the details are where most programs fall short.
Water needs to be close enough that getting it doesn’t feel like a detour from the job. IHSA and CCOHS guidance points to drinking small amounts frequently rather than waiting until you’re thirsty, about a cup every 20 minutes. CCOHS is fairly measured on electrolyte drinks specifically, recommending plain water as the default and sports drinks only in moderation for workers doing genuinely heavy physical work, since too much added sugar or salt can cause its own problems.
Shade means an actual rest area, not a technicality. IHSA notes that the spot shouldn’t be so cold it causes its own kind of shock; somewhere around 25°C is the sweet spot, with airflow if you can manage it. A tree at the far end of a lot that nobody actually walks to on a ten-minute break doesn’t count for much.
Rest needs to scale with conditions rather than follow a fixed schedule regardless of the day. A mild morning and a 35°C humidex afternoon call for different break frequencies, and your program should reflect that difference. This is exactly what OHCOW’s Humidex-based Heat Response Plan is built for: tying your response to measured conditions rather than a guess.
The second framework, acclimatization, is the one that tends to get the least attention and probably deserves the most.
CCOHS guidance puts full heat acclimatization at roughly six to seven days, and some people need longer. New workers are advised to start at around 20 percent of their normal exposure on day one, increasing by no more than 20 percent each day after that. Workers coming back after time away get a faster ramp since they’re rebuilding tolerance rather than building it from scratch, typically starting around half their normal workload on day one and reaching full capacity by around day four.
Heat tolerance starts fading after just a few days off the job and can disappear almost entirely after three weeks away, so this isn’t a one-time onboarding step. It needs to apply every time someone’s been off for a stretch. The body’s ability to handle heat is a physiological adaptation that takes real time to build, not something willpower can substitute for.
The catch is that new workers are often in the worst position to ask for a lighter week. They’re trying to prove themselves. They don’t know the culture yet. Bringing it up themselves is the last thing they’re likely to do. Which is the same structural point as before: the acclimatization schedule needs to be assigned to them, not left for them to request.
What this looks like on a real site
A heat program that actually works isn’t a poster in the trailer nobody reads. It’s a few minutes in the morning toolbox talk covering the day’s conditions and what that means for break timing. It’s a rest area that’s already set up before anyone needs it. It’s a buddy system for the first week or so for anyone new on site, so someone’s keeping an eye out without it feeling like a performance review. It’s water that’s actually cold, actually close, and actually part of the conversation rather than an afterthought.
It’s the foreman calling a ten-minute break at 10:30 and not leaving any room for it to feel optional.
The guys who never ask for a break aren’t weak and they’re not careless. They’re doing exactly what the culture told them to do. I know because I spent years reinforcing that culture without thinking twice about it.
Getting this right isn’t complicated. It’s just a decision you have to make before it’s hot out, not after someone goes down. Build it into the day, make it normal, and nobody has to be the guy who asked.
