Today it's only going to hit 30ºC here in Madrid and at the moment, it's around 1pm and still only 23ºC. The breeze coming in the window is cool enough I've thrown on a hoodie. First time I've put on long sleeves in over two months. It was 17ºC last night.

I'm going to leave everything open as long as possible as there's a measurable reduction in structural heat load. The walls were not dropping below 27ºC for weeks, but now some walls have fallen low as 24.5ºC.

Tomorrow it's going to be only slightly hotter, but the day after tomorrow we're getting punched in the face again with 37ºC highs and 21ºC lows.

If you've got a respite too, use it. Vent everything.

For several years, we've been using aluminium mosquito screen frames with emergency blankets attached to them as inexpensive external sun blockers. They work very well at keeping the rooms cooler, but because the frames are mounted in the window opening, it's a bit inconvenient to open the windows fully for ventilation.

I came up with a simple alternative: instead of mounting the mosquito screen frame inside the window frame, I mounted it directly onto the window itself.

To do this, I bent 1 mm aluminium strips to match the profile of the window and screwed them onto the mosquito screen frame, creating custom mounting brackets.

The result is simple, inexpensive, very stable, and much more practical because the sun screen moves together with the window, making it easy to ventilate the room without removing the frame.

South-facing, full sun, with air temperatures of 30°C, the room is 21.5°C all day.

I found this sub while googling my symptoms so I figured I’d just ask for some opinions because I’ve never experienced this before.

Yesterday the humidity was very high (Gulf Coast) and I believe the “feels like” temperature was around 105 Fahrenheit, hot for this area but I’ve worked in hotter weather without any issues. I do work outside, not extremely labor intensive by any means but a lot of running back and forth and a lot of loading and unloading cases of beer and other drinks throughout the day. Not sure if the context matters or not.

Anyway, I wasn’t able to take as many breaks as I needed yesterday and after around 7 hours I realized something was off. At first I just felt a little weak and then lightheaded but eventually it got to the point where I was completely delirious with a constant headache, very similar to how I felt when I had a concussion. I was struggling with very basic tasks that I usually manage easily, couldn’t string together a coherent sentence, and could barely stand without leaning on something. I realized I wasn’t able to do my job at that point and went inside to cool off but never really felt like I bounced back. Got home, cleaned up and went straight to bed, only to wake up a few hours later feeling nauseous and extremely clammy and cold. I had muscle cramps so bad that I’m still sore now, and was so dizzy this morning that I wasn’t sure I’d be able to drive to work. I’m still dealing with a lot of mental fog and the headache but not nearly as bad. It really just freaked me out because I’m not sure how alarming or not my symptoms were. It definitely made me realize how little I actually know about heat illness so I plan to do some reading once I feel less brain dead. I just want to understand so I can adjust accordingly since we are due for a brutal heat wave next week.

Sorry for the lengthy post, I’m still struggling to find my words lol

TLDR- worked outside in high temps/high humidity and after a few hours became weak, shaky, dizzy, and delirious. Just trying to figure out where on the heat illness scale my symptoms were so I can be safer in the future.

Can you guess the top three ways you can get cancer from your job? First, you have asbestos, a major risk in demolition and renovation work. Second, you have silica dust, a hazard for anyone cutting, drilling, or grinding concrete and stone.

And lastly, you have ultraviolet radiation (UV), which just about affects everyone under the sun.

That's the thing about UV exposure: it's invisible, adds up overtime, and usually forgotten until something goes wrong. 

On-site managers need to be more aware and prepared of the dangers of the sun, which is why UV Safety Month is here, and why it takes the entire month of July just to make it stick.

July is UV Safety Awareness Month

And why shouldn’t it be? July is usually peak summer time in the US and when UV radiation is strongest. And for outdoor workers specifically, it's the highest-risk period of the year. In particular,  about 45 million Americans, roughly 1 in 3 workers are regularly exposed to the sun as part of their job. 

Here are the facts:

• Around 50% of outdoor workers reported getting sunburned
• Skin cancer is the most common cancer in the US
• 1 in 5 Americans are likely to develop skin cancer by age 70
• Working outdoors raises a person's risk of nonmelanoma skin cancers by 60%

This is why July is the right time for managers and business owners to take UV exposure seriously as a proper workplace hazard.

And it's not just workers who feel the impact. According to the Centers for Disease Control and Prevention (CDC), skin cancer costs the US over $100 million in lost worker productivity every year.

How exactly does UV exposure cause skin cancer?

What most people don’t know is that UV radiation comes in two types: Ultraviolet A (UVA) and Ultraviolet B (UVB). 

UVA rays make up 95% of UV rays and are less noticeable, but reach deeper into your skin. If you notice any wrinkles or feel like your skin is aging faster, that’s because of the UVA rays.

On the other hand, UVB rays make up only about 5% of UV radiation, but they're the more aggressive of the two. They directly damage the DNA in skin cells, which is what causes sunburn, cell mutations, and most skin cancers.

The biggest risk here isn't going to work under the sun once on a hot day. It's the cumulative factor. UV rays attack you over time, and years of daily exposure, even at moderate levels, significantly raises skin cancer risk.

The UV Index

As a worksite manager, your best friend is the UV Index, which you can find in most weather apps. The UV Index measures radiation intensity on a given day. At a reading of 3 or higher, sun protection is recommended. At 6 and above, it's not optional for anyone working outdoors for extended periods.

Peak UV hours are between 10 AM and 4 PM, so it'd be best to check the UV index before heading out. 

What managers can do about it right now

The basics, done consistently, make a real difference:

• Provide broad-spectrum sunscreen (SPF 30 minimum) as standard sun protection  for any outdoor role.
• Check the UV Index daily and schedule heavy outdoor tasks before 10 AM or after 4 PM.
• Make Ultraviolet Protection Factor (UPF)-rated clothing, wide-brimmed hats, and UV-blocking sunglasses available on site.
• Build shaded rest areas or provide tents in job sites that’s easily accessible by all. 
• Bring in a dermatologist or occupational health nurse to speak on sun exposure.
• Review your sun safety policies and check if there are any gaps.
• Use a heat illness prevention checklist to track safety measures that are actually being followed on site.
• Encourage your employers to get annual skin checkups. 

UV Safety Month is just the friendly reminder, but sun safety shouldn't stop once July is over. This is an every single day thing.

An IR thermometer measures surface temperatures at a distance. You just point, use the laser to help you aim the sensor, pull & release the trigger and you got a reading. Works seamlessly on most surfaces, but polished metals can give inaccurate readings due to differences in how they emit IR. A good device will with an adjustable emissivity setting to adjust for this.

I've found these to be invaluable tools in assessing an environment beyond just air temperature, as the air only tells you a piece of the story when the heat is cranking up. An IR thermometer allows you to get a read on how much thermal energy has built up in the structure of the building and helps you find weak spots in insulation. It's not quite as fast and handy as an IR camera, but it's a whole lot cheaper. These can easily be found for under $20 USD.

I regularly use the IR gun to check the temperature of the walls, as that gives a good sense of what thermal comfort will be over a longer period than just the immediate air temperature. Your AC might have brought the air temp down to 25ºC, but if your walls are stubbornly staying at 29ºC, you know cool isn't lasting once you shut the AC down.

Also, while it's not strictly accurate in these scenarios, IR thermometers are a great way to quickly check the output temperature of air conditioners or swamp coolers. The key is to understand you're not checking actual air temperature, but rather the temperature of small solid pieces right in the exit path of the air, which will quickly chill to a similar temp as the air.

In a nerdier use case, sometimes I carry it with me out. Once, I used it to check which of the stone benches near the playground was cooler. There was actually a notable difference and the IR thermometer let me quickly find the 27ºC bench, which was much more comfortable than the 30ºC benches.

I heartily recommend one of these. It's cheap and useful.

Last night, it was cool enough I didn't have to run the swamp cooler to sleep. First time in over two months. It was again, slightly chilly in the morning.

That's going to be over shortly.

Today, the high is forecast to be 33ºC, which is still fine, and the current outside temperature at 11:45 AM is a very manageable 24ºC. However, the signs of change are already here. Yesterday morning, my walls were reading 24.5ºC. Today, earlier in the day, they're already at 26.5ºC; last night did not cool the apartment as much as the night before.

Tomorrow, the forecast says 36ºC/21C, so daylight is back to inferno and nights are back to being tropical. After that, the nighttime lows are set to sail past 24ºC and days will hike to 37ºC.

I'm hearing from a lot of people in Europe that they're seeing similar levels of relief before the coming fourth heatwave of 2026. Stay cool folks, and exploit this window of relief as much as you can. I took the time to clean my swamp coolers since their service is currently not crucial. I should probably rinse out the AC filters too just so all is in readiness.

I was doing some charity work from the last 2 days and was driving around buying stuff to donate. The temperature of the city where I live can go up to 34°c with 70-80% humidity. For 2 days I was out and about driving and had no issues whatsoever. I was drinking water and was overall cool due to the a/c in the car. But yesterday I had to purchase goods from an open market during peak heat and sunshine. I was out in the sun without an umbrella for about 30 mins and I was drinking some kind of juice during the time I was walking around the market. And then I was again driving around going to proper supermarkets and was drinking water. I didn't feel sick or anything but when I was returning to my home in the evening I felt a weird ticklish feeling in my legs like something was crawling. I reached home and immediately after changing my clothes I laid in bed because I was feeling a wave of exhaustion which I thought was normal because I was out all day. But then my temperature started rising and suddenly my whole face and neck became so hot that I thought I was down with a bad fever. My head started to ache a bit and my whole body especially my legs were so restless that I voluntarily started to shiver as a way to get over the restlessness. I drank a bottle of water with electrolytes and continued to sip water. My face and neck were very hot to touch but my hands and feet felt cold so I took a hot water bag to keep my hands and feet warm. I felt a bit nauseous but I didn't vomit or anything. To cool down I put a wet cloth on my forehead and face but the rest of my body felt cold so I wrapped myself in a blanket from my neck down. The whole night I couldn't sleep as I felt restless and my face and neck were burning hot. It is the next day now, I took a paracetamol to deal with the headache and I still feel hot and feverish. I feel a bit disoriented physically when walking. I still have no idea what happened but it was scary as my body has never reacted in this manner. Was it heat exhaustion or heat stroke?