Q: "It's so hot outside, you could fry an egg on the sidewalk!" exclaims Chesky Chamowitz as he walks into his house one scorching Shabbos afternoon.
Chesky and his family live in Phoenix, and temperatures get pretty hot in the summer - sometimes over 110 degrees Fahrenheit! This means that any surfaces, especially dark surfaces that absorb heat, get super hot.
Chesky suddenly stops in his tracks. "Hey, maybe we should fry an egg on the sidewalk! Even better, I'll put your old dark purple shirt on the sidewalk, so it'll absorb all the heat, and I'll put the egg on there. That would be really cool!"
"You mean really hot," says Chesky's sister Chaya. "Either way, I'm not sure you are allowed to cook an egg on the sidewalk - or on a shirt - on Shabbos." "But I learned that cooking in the sun is permitted on Shabbos!" says Chesky.
Is Chesky correct?
A: Chesky is right, but so is Chaya! While cooking directly in the sun (such as placing a cup of water in the sun until it heats up) is permitted, cooking using toldos hachama, something heated by the sun (such as a hot sidewalk) is forbidden midiRabanan, since it can be confused with cooking with toldos ha'aish.
(בישול, בישול באופן כללי, הגדרת האיסור, פרק ד‘, סימן א‘, סעיף ד‘, דוגמא 1)
