Trigger mittens, or trigger finger mittens, have been used by the American military
since at least the Civil War. A clever combination of the warmth of mittens with the
flexibility of gloves, these mittens have a separate index finger to allow soldiers to easily
operate machinery in cold temperatures. However, they're great all-purpose mittens for
civilians as well. I've updated the design for the 21st century by adding a small slit in
each thumb and index finger so you can slip your fingertips out for cell phone or touch
screen use.
These mittens can be made in either men's or women's sizes with just a change of
gauge and finger length. For the most part the patterns are identical, but where there's a
variation, men's sizes are given in parentheses.

Supplies:
For men's mittens:
Four US 6 dpns (or size needed to obtain gauge)
Gauge: 5 sts/inch
For women's mittens:
Four US 5 dpns (or size needed to obtain gauge)
Gauge: 5.5 sts/inch

For all mittens:
Worsted-weight yarn; I used Lion Brand Fishermen's Wool
Ruler or tape measure
Stitch markers
Stitch holder or scrap yarn
Weaving needle

Abbreviations:
CO - cast on
BO - bind off
k - knit
p - purl
st(s) - stitch(es)
sl - slip
rnd - round
kfb - knit front and back
pm - place marker
k2tog - knit two together decrease
ssk - slip, slip, knit decrease
dpn(s) - double-pointed needle(s)