If you put hot food in the fridge, you risk spoiling the other food in there.

I've been talking about conditional sentences the past two days:

http://upgradeenglish.blogspot.com/2009/06/if-you-dont-understand-conditional.html
http://upgradeenglish.blogspot.com/2009/06/if-you-dont-get-to-station-before-last.html

First, to answer the questions from yesterday:

If I hadn't been there to help him, he might have had to sleep on the street. <- third conditional It's late now. If I don't go to bed, I'll be really sleepy tomorrow. <- first conditional

Today, I want to talk more about zero conditional. About grammar, zero conditional often uses present tense in both the "if" clause and the main clause.

If you speak English <- "if clause", present tense (現在形) traveling abroad is more convenient. <- main clause, present tense (現在形)

We often use it for things related to science:

If water reaches 100 degrees, it boils. (boil = 煮える, 沸く)
If surgeons do not disinfect their instruments, their patients get infections. (surgeon = 外科医; disinfect = 殺菌する?; patient = 患者; infection = 感染)

We use it for facts:

If you live in Tokyo, you have to deal with crowds. (deal with = 扱う; crowd = 群衆)
If you live in West Texas, you have to deal with dust storms. (dust storm = 砂塵嵐)

We use it for rules:

If you speed while driving and the police see it, they usually give you a ticket. (ticket = 違反切符)
In tennis, if you allow the ball to bounce twice on your side of the court, you lose the point.

We also use it for things related to our habits or characters:

If I don't listen to music during the day, I get grumpy. <- it's true! (grumpy = イライラする)
If I don't have a cup of tea in the morning, I remain a zombie for an extra half hour. <- it's true, too!

I cooked some vegetable soup for dinner, which I put buckwehat noodles into. Right now, the soup is sitting on the stove. It's cooling down. In a while, I'll put it in another container and put it in the fridge. The reason is that if you put something hot in the fridge, it heats the other food there. That increases the risk of food spoiling.

I have a weak stomach. If I eat something that isn't really fresh or has gone slightly bad, my digestive system is a mess for days. As a result, I don't want to put the soup in the fridge right away.

If you ever have a question, you should ask me.