Here's what I do, dampen a towel and put it in the freezer. Once the towel is good and cold wear it like a cape. Looks kinda stupid but you'll stay cool.

Avoid being out in the midday sun. If you do, try to walk in the shade as much as possible.

If your windows have external shades close them down when the sun is hitting that side of the house/appartment so that the heating up of objects from the sunlight happens outside not inside.

Wear shorts/skirts and loose clothes of thin textites that don't retain much heat (such as cotton).

If you're going to be out for long periods, bring water, ideally cold water.

Sure, if you have AC or, even better, a swiming pool, it's a lot easier to keep cool, but these suggestions will work even for those who can't afford those things.

I live in the desert so its usually a dry heat so I get to use a evaporative/swamp cooler. It uses way less electricity than the AC. I just have to crack open a few windows across the house and turn on a fan in the hallway and it gets quite cool and doesn't get too humid inside. It hit 110ºF (43ºC) today and it never got above 72ºF (22ºC) inside.

People have already mentioned wet towels on your neck but I would add, if you can, cold wraps for your legs: wet towels around your calves.

Ever since I started riding (motorcycles) I don't even really notice it anymore. Anything less hot than "armored jacket and helmet under the sun" just doesn't register as hot anymore

If you don’t have air conditioning you can create a shitty version using a bucket of water, a towel and a fan. Just have the towel wick up the water and lay it over the fan.

I need AC for about 6 months out of the year (used to be three, maybe three and half) here in the east/south US. The humidity is so bad it makes 90F seem like 110F and even the shade won't cool you down and it drops very little when the sun goes down.

I'm replying because my electrical panel is being replaced right now and I have no power (the router is on a batt backup)...it heated up in here and I'm able to psychologically deal with it for now....if the installation goes south and I'll be without power for more than a few hours I'll take the cat and head to my sister's place :)

In the Philippines, Filipinos usually go to malls for free air-conditioning since electric bills here in the country is not very friendly in terms of the costs. If you are lucky enough to be in the middle class, running the AC during afternoon for some hours is enough already.

I'm late to this party because I'm on the other side of the planet in a sub-tropical climate. I agree with the commenter from India and want to add:

• if you have a cotton cap / beanie / soft hat, get it out Wet it, wring it out, and put it in your freezer in roughly the right shape for your head. Use whatever is in the freezer to shape it, then let it freeze. Remove from freezer, put it in your head, and thank me for the brief but blessed relief.

• Wear a light cotton long sleeve top. Wet the sleeves and stand or sit in front of a fan or in a breezy spit in the shade. It's like air conditioning for your skin.

• Wet your head for instant relief. Your wet hair will help keep you cool for longer.

• Plan your day around the heat. If you have to go out, do it as early in the day as you can to avoid the heat. Stay in the shade as much as possible, but somewhere with good air flow

I’ve discovered that if I have one little air conditioned place I can go, then I don’t actually need to be in it for it to be a relief.

Just knowing that after this day in the year I’ll have a place to cool off really helps.

Always humid heat, days above 35 degrees have increased a lot. Have to use an AC all summer long... Prayers to those who have to work outside.

In FL: Air conditioning.

In HI: Breezes, fans.

Drink lots of cold water. Back in May I almost got a heat stroke because I was drinking room temperature water and hot tea @ 4pm when it is the hottest. Stop drinking anything hot. If tap water is warm fill up buckets of water previous night for bathing. Leave those buckets open in the bathroom with windows open to allow water to cool overnight. Of course you also need air-conditioning and ceiling fans. Additionally, use blackout curtains on windows, keep doors and windows closed so that rooms don't become as hot as outside. FYI where I live summer temperatures are 45 deg C, and this is all part of what I do to deal with the heat.

Honestly, I just love the heat. I strip down to as few layers as possible, put a fan on, and that's pretty much it. Even when it gets really hot, I still find that easier than the cold. The question I really want to know is how do people deal with the cold!

• Take bath multiple times a day.
• Drink tender coconut or butter milk, whichever you get.
• Wear cotton clothes.
• Drink lot of water to avoid getting kidney stones.
• Don't drink ice water.

Barcelona A/C all the day at 24C (25C or 26C when sleeping). However to me it's been always hot here. So I'm not particularly suffering this summer more than the others.

I stay inside with AC on as much as I can for June, July, and August. I know many homes in Europe don't have AC, but if we didn't have it here, we would likely have very high heat-related death rates. It has been 100-104°F (38-40°C) almost every day for the past 6 weeks. And at night, it only gets as low as 80°F (26.5°C). It's brutal. So AC is the answer.

But from mid September through the end of May, we can be outside almost the whole time. There's the occasional cold snap in winter, but on a regular day, it can be as warm as 80°F (26.5°C) in December and January.

I live with no AC. First thing, all windows get blocked with blackout curtains or whatever you can find. Wear loose cool clothes. I like to wear linen. At night and early morning/dusk, open the windows and doors (if applicable) to get the cool air flowing through your place. If you can, keep them open all night and seal them up once the sun comes up. Use a fan to blow directly on you. Even when it's hot, that air flow is a life saver. Misting yourself and standing in a fan is a very effective way of keeping yourself cool. All your physical labor chores you're going to want completed early in the day or after the sun goes down.

As for your laptop, maybe pointing a desk fan at the keyboard may help?

I'm in Phoenix. It was 112°f here today. It's hot as balls.

However, I'm immensely more comfortable in this heat than I was when visiting Germany last summer when it was in the high 70's. The difference is the humidity. I was constantly sweating, soaking everything while I was over there. Here? I get a little sweaty at 100°, sometimes. Our power infrastructure is pretty solid, so lots of air conditioner.

A neck towel that you regularly wet is truly amazing

Midwestern US here, it's been getting hotter and some years our AC just stopped working. I keep my fan turned on almost 24/7 as I can't breathe well without it on and recently I got blackout curtains with angled curtain rods. Keeps my room much cooler than a blanket over the window

Without HVAC (which I'm assuming is the case) your options are limited. I would look into fans and evaporative coolers.

There are also freestanding compression-based units that have you run tubes out the window, but avoid single tube models!

I haven’t seen anyone recommend this yet but for your body itself, try using peppermint castille soap. There’s a brand here called dr.bronners, not sure if you have it in your area but you might be able to find it on Amazon. Really helps keep skin cool, sometimes I’ll just bathe my feet in it if I’ve already showered and just need to cool off a bit.

Also lose the socks and general clothing if you’re at home. A wet rag over a fan may help as well. Drink lots and lots of water. Horror movies also sometimes give me a bit of a chill! Good luck!

You want to get some nice blackout thermal curtains for any windows facing south. You might actually need 2 sets of curtains to fully block the sun. I've noticed a big difference this year since I added a 2nd thermal curtain on top of the 1 I had. Unfortunately that only helps so much and as long as it's unbearably hot outside you're going to see the heat increase inside as the day goes on. At night open all of your windows and run fans to get as much airflow as possible while it's cooler outside. In the morning close your windows the minute the outside temperature is the same as the inside temperature. As long as it's cooler outside, the windows should be open.

I'm from central Italy, in my city temperatures regularly reach 40 degrees in August. With the recent heatwave we reached it in mid July, I cope by being indoors and locking myself in with AC on and drinking ice cold water, and when I can (and I fortunately can afford so) going on vacation in colder, still close, places, something like Abruzzo or Molise if you know central Italy.