So I'll break this down into two fields because that's easy, and while I do think the original idea of 'Go out and catch 'em all' is amazing, I am taking some personal things into consideration.

My little brother is ten years old and his summer is almost over. When he's not at summer camp he's home getting ready to rest and on days when he's home he lives in an area that's semi-popular with Pokestops and stuff but again- he's ten years old. Parents, myself, and his grandparents work so they can't just take him out everywhere at all hours of the day. He has a location spoofer and I'm all for it because of his ten-year-old code of 'honor'. He's not taking any gyms in other cities and/or states, and isn't exploiting locations for exclusives (For instance: He isn't teleporting to Japan because he wants to actually go there to catch 'em all.) because he says it's unfair to people. He quite literally just wants to catch them all in the USA and just keep his favorites close. I'm perfectly fine with him doing it. That being said, he much rather prefers it when we get on our skateboards and go find them ourselves.

Now if you're a grown woman/man and you're spoofing stuff to 'be the best' then I disagree with that completely, you're an adult and you know how to take care of yourself and -in most cases- have the means to do so, so no, don't do that. But my little brother and my pal who's stuck in a wheelchair spoof and I am completely fine with them doing it.

Don't do it just because it's hot outside though, get a friend or two and go somewhere when the sun is down and bring water, then your problem is solved and you enjoy the game how it was intended to be played. But if you're physically unable to do that then spoof away but do so responsibly.