Heat Wave is a mini-game in the Nintendo DS and DSiWare versions of Plants vs. Zombies. It is the tenth mini-game within the game and replaces Big Trouble Little Zombie in Level 3-5. Throughout the mini-game, the game limits the player to four Peashooters, four Lily Pads, and two Wall-nuts. They must move the plants around the lawn to defeat the incoming zombies.
Shift your Peashooters around as needed, allocating one row's unneeded defenses toward another, so as to maximize efficiency. For example, if you have a normal Zombie in one row and a Buckethead Zombie in another, drag about three of the Peashooters from the normal Zombie's row into the Buckethead Zombie's row. Remember to make noise into the device's microphone when the word "Shout" appears on the bottom of the heat meter.
As you progress, some Peashooters will get tired and stop shooting as fast as usual. When you next shout into the microphone, these Peashooters will all turn orange and begin firing at an increased rate, sometimes along with others. Again, move Peashooters around as efficiency dictates. Try to conserve your Wall-nuts and save them for tougher Buckethead Zombies and remember that the Zomboni and Gargantuar cannot be stopped by Wall-nuts. Move the Peashooter and blow in the mic, so the Gargantuar's Imp does not eat your Peashooters. If the Gargantuar gets too close, stall him by moving a Wall-nut in front of him and move it away when he lifts his arm to pound indefinitely.
- This mini-game replaces Big Trouble Little Zombie, since the smaller zombies would be difficult to see due to the small resolution of the Nintendo DS.
- Although the game tells the player to shout "HEY!" into the microphone, simply blowing into the microphone, tapping on or talking at a normal level will work just as well, also regardless of what the player says.
- It is one of the only mini-games where the plants can be moved around to different locations within a level, the others being Beghouled and Beghouled Twist. However, it is the only mini-game in which plants can be moved where the player wants, as plants within the other two move sequentially.
- It is possible that enough peas can be fired in a single row that a zombie can be killed after all the Peashooters have been removed from that row.
- If at least two plants have been destroyed by the end of the level, the Gargantuar may drop two seed packets: one after death but before falling over, and one after disappearing from the lawn.
- As with other mini-games where seed packets are dropped within a level (e.g. Slot Machine, It's Raining Seeds, etc.), the seed packets will disappear after a certain amount of time if not used.
- There is a glitch that shows the Peashooters as black glitched shapes, which may flicker into beta graphics. There may have been a "shout meter" for each plant. The glitch Peashooters are shown normally while being moved and have red spirals when they are strengthened.
- It is not available in any other version besides the Nintendo DS version.
- The heat does not destroy ice trails any quicker than in normal levels.
- It is the only mini-game in which a special sound effect is used.
- There is a bug where if the player has purchased the Wall-nut First Aid and one of their Wall-nuts is damaged, they can move the undamaged Wall-nut on top of the damaged one. It will not replace the damaged Wall-nut, and they will just both sit in the same place.
- A lens flare effect can be seen in this mini-game.