ARCADIA, Calif. (KABC) -- In the battle of man versus mosquito, Andrew Crabtree of Arcadia is getting ready for war.
"They told us to bring deet, bring a lot of repellents," said Crabtree.
He's part of a medical mission to Honduras, so the Zika virus is a top concern. He's asking his dermatologist Dr. Shirley Chi for help.
Experts recommend 20 percent deet products for children and up to 40 percent for adults. But you have to be careful because deet can melt synthetic materials such as your backpack or watchband.
"The concern is if deet is dissolving plastic, how good could it be for your skin? We know deet is very sensitive to people who have allergies, and a lot of people are allergic to deet," Chi said.
She added deet also can be neurotoxic if used in high doses in children. For this reason, Chi prefers the ingredient picaridin.
"Picaridin, 20 percent, can only be applied once every eight to 10 hours ... and that's good for kids because you're applying less," she said.
Another trick is instead of buying expensive permethrin-treated clothing, spray your own. Chi advises her patients to focus on spraying around the neck and arm openings.
Permethrin sprays last up to six washes, but make sure you don't spray permethrin directly onto your skin because it can be very irritating. So before you put on your clothes, make sure the material is completely dry.
"It will repel insects. And so people are treating their tents and camping gear with permethrin, which is great," Chi said.
Many experts recommend putting on sunscreen first then the repellent, so the mosquitoes can smell it. But since sunscreen needs to be re-applied more often than repellent, Chi says it's OK to re-apply sunscreen on top of the repellent you already have on.
That's important for Crabtree, who wants to avoid bites and burning.
"You can never be too careful," he said.
These are tips he can use in the rainforest and here at home.